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In pursuit of the “double carbon” objectives, converting high-carbon thermal power plants into carbon capture power plants is recognized as an effective measure to mitigate carbon emissions. In order to improve the economy of the system, an electric hydrogen generation unit is introduced, and an economic dispatch strategy that considers the combination of a flexible carbon capture power plant and electric hydrogen generation is proposed. Firstly, the low-carbon principle of the flexible carbon capture plant is introduced, and secondly, the joint operation structure of the flexible carbon capture plant, pumped storage, and hydrogen generation is constructed in order to fully exploit the synergistic operation potential of the hydrogen and carbon capture plants. On this basis, an economic dispatch model with the objective of the lowest combined system cost of the sum of system operation cost, system carbon trading cost, hydrogen production revenue, and wind and light abandonment cost is established, fuzzy parameters are used to characterize the uncertainty levels of wind and light, fuzzy opportunity constraints are established, and the model is solved using an improved sparrow search algorithm. The results of the example show that the proposed model reduces the comprehensive cost by 20.9% and carbon emissions by 61.77% compared with the existing model, which has significant low-carbon economic benefits. [ABSTRACT FROM AUTHOR]

Effects of pulse electric field (PEF) on antioxidant activity of pine nut ( Pinus koraiensis ) peptide were discussed using H 2 O 2 -induced HepG2 cells and changes of peptide structures were measured by MIR, NMR and CD spectra. Using HPLC-MS/MS, a novel peptide was identified as QDHCH. After PEF treatment the DPPH and ABTS radical inhibition, and CAA values of QDHCH were increased to 85.13% ± 0.17%, 95.45% ± 0.12%, and 4670.10 μmol of quercetin equivalents/100 g. The PEF-treated QDHCH has better protective oxidative stress inhibitory of 74.22 ± 3.70%, and the T -SOD, CAT, GSH-Px and GSH-Rx activities in cells were significantly increased by 91.92, 7.98, 18.5 and 18.79 U/mg prot, while the MDA content was decreased to 8.45 ± 0.71 U/mg prot compared with H 2 O 2 damaged group. In addition, the hydroxyl radical scavenging activity of QDHCH was increased by 10.53%; the basic structure was not changed by PEF, while the influenced secondary structures may induce the antioxidant activity improvement in HepG2 cells. [ABSTRACT FROM AUTHOR]

Endocellulases are one kind of the important biodegrading cellulose enzymes. Experimental results show that a rotated and distorted preactivated structure exists before the substrate entering the transition state. The molecular dynamic simulation of endocellulase Cel6A models revealed a correlation between the rotation and distortion of pyranoside ring in −1 glycosyl unit of the substrate. The two key residues, Tyr73 and Ser189, in Cal6A cooperate to rotate and distort the pyranoside ring in the cellulose hydrolysis. [ABSTRACT FROM AUTHOR]

Abstract: The acylpeptide hydrolases from hyperthermophilic archaeon Aeropyrum pernix K1 has a short conserved N-terminal helix in its family. The role of this N-terminal helix in the function of the hyperthermophilic enzyme, however, is unknown. Here, we investigated this question by protein engineering and biophysical methods. We found that a mutant (ΔN21) with the N-terminal helix deleted is no longer functional at the optimum temperature for WT enzyme (95 °C), required for the survival of Aeropyrum pernix K1. Instead, ΔN21 has the optimum activity at ∼77 °C, with higher activities than the WT enzyme below this temperature. ΔN21 is less stable than the WT enzyme and started unfolding at ∼77 °C, indicating that the loss of the enzymatic activity of ΔN21 at higher temperature is due to its low thermodynamic stability. In addition, we found that the salt bridges formed between the N-terminal helix and the catalytic domain of the enzyme play only a minor role in stabilizing the enzyme, suggesting that hydrophobic interactions mainly contribute to the stabilization. Since the N-terminal helix is conserved in this family of enzymes, our results suggest that the N-terminal helix is likely to play an important role for stabilizing all other enzymes in this family. [Copyright &y& Elsevier]

Abstract: A novel plasmid, pBSR2, was constructed by incorporating a strong lipase promoter and a terminator into the original pBD64. A mature lipase gene from Bacillus subtilis strain IFFI10210, an existing strain for lipase expression, was cloned into the plasmid pBSR2 and transformed into B. subtilis A.S.1.1655. Thus, an overexpression strain, BSL2, was obtained. The yield of lipase is about 8.6mg protein/g of wet weight of cell mass and 100-fold higher than that in B. subtilis strain IFFI10210. The recombinant lipase was purified in a three-step procedure involving ammonium sulfate fractionation, ion exchange, and gel filtration chromatography. Characterizations of the purified enzyme revealed a molecular mass of 24kDa in sodium dodecyl sulfate–polyacrylamide gel electrophoresis, maximum activity at 43°C and pH 8.5 for hydrolysis of p-nitrophenyl caprylate. The values of K m and V m were found to be 0.37mM and 303μmolmg−1 min−1, respectively. The substrate specificity study showed that p-nitrophenyl caprylate is a preference of the enzyme. The metal ions Ca2+, K+, and Mg2+ can activate the lipase, whereas Fe2+, Cu2+, and Co2+ inhibited it. The activity of the lipase can be increased about 48% by sodium taurocholate at the concentration of 7mM and inhibited at concentrations over 10mM. [Copyright &y& Elsevier]

Accurately assessing the state of health (SOH) of lithium batteries is of great significance for improving battery safety performance. However, the current assessment for SOH suffers from the difficulty of selecting health features and the lack of uncertainty using data-driven methods. To this end, this paper proposes a health state assessment method for lithium-ion batteries based on health feature extraction and an improved Informer model. First, multiple features that can reflect the SOH of lithium-ion batteries were extracted from the charging and discharging time, the peak value of incremental capacity curve (ICC), and the inflection point value of differential voltage curve, etc., and the correlation between multiple health features and the health state was evaluated by gray correlation analysis. Then, an improved Informer model is proposed to establish a health state estimation method for lithium-ion batteries. Finally, the proposed algorithm is tested and validated using publicly available battery charge/discharge datasets and compared with other algorithms. The results show that the method in this paper can realize high-precision SOH prediction with a root-mean-square error (RMSE) of 0.011, and the model fit reaches more than 98%. [ABSTRACT FROM AUTHOR]

Recently, the press-pack insulated gate bipolar transistor (IGBT) has usually been used in direct current (DC) transmission. The press-pack IGBT (PPI) adopts a parallel layout of boss chips, and the currents of each chip will be uneven in the process of turning on and off, which will affect the reliability of the device. To measure the currents of each chip, based on the analysis of the principle and equivalent model of the Rogowski coil, this paper puts forward the design scheme and design index of multi-layer printed circuit board (PCB) Rogowski coil with good high-frequency performance, strong anti-interference ability and sufficient sensitivity. With the simulation analysis of Altium Designer and ANSYS softwares, a 1 mm thick, 76-turn integrated four-layer PCB Rogowski coil is designed. Then, adding a composite integrator, an integrated Rogowski coil sensor for measurement of PPI chips currents is designed. The Pspice simulation and the experiment results show that the sensor is fully satisfied with the chip current measurement. [ABSTRACT FROM AUTHOR]

Rational cobalt phosphide/carbon (CoP/C) complex film composed of densely assembled CoP-in-carbon nanosheets was successfully constructed via filtration-induced self-assembly and in-situ transformation strategy. The successful implementation of this method relies on the morphology controlled preparation of graphene-like Co alkoxide by varying the chain length of polyols to regulate the polycondensation process. The graphene-like CoP-in-carbon construction units can accelerate ions/electrons transportation and guarantee structural robustness. Thanks to its ideal composite structure, CoP/C complex film exhibits outstanding cycling and rate performances, including high capacities up to 920.5 mAh g−1 over 200 cycles at 1 A g−1 and 826.5/662.3 mAh g−1 after cycling under 2/4 A g−1 over 1000 cycles. Besides, full-cells constructed with CoP/C complex film anodes and LiCoO 2 cathodes exhibit superior cycling stability and reliable capacities of 773.4/518.7 mAh g−1 after 200 cycles at high rates of 1/4 A g−1. Such efficient and reliable strategy can offer new insights and understanding about the construction of advanced film materials for energy-storage devices. [Display omitted] • Polyols mediated growth of graphene-like cobalt alkoxide nanosheets. • Alkoxide film constructed by filtration-induced self-assembly • CoP/C complex film prepared by in-situ transformation strategy • Fascinating lithium storage behaviors affected by structural features [ABSTRACT FROM AUTHOR]

Age-related macular degeneration (AMD) is the most common blindness-causing disease among the elderly. Under oxidative stress, low-density lipoprotein in the outer layer of the retina is easily converted into oxidized low-density lipoprotein (OxLDL), which promotes the development of choroidal neovascularization (CNV), the main pathological change in wet AMD. Liver X receptor (LXR), a ligand-activated nuclear transcription factor, regulates various processes related to CNV, including lipid metabolism, cholesterol transport, inflammation, and angiogenesis. In this study, we evaluated the effects of the LXR agonist TO901317 (TO) on CNV. Our results demonstrated that the TO could inhibit OxLDL-induced CNV in mice as well as inflammation and angiogenesis in vitro. Using siRNA transfection in cells and Vldlr−/− mice, we further confirmed the inhibitory effects of TO against the inflammatory response and oxidative stress. Mechanistically, the LXR agonist reduces the inflammatory response via the nuclear translocation of NF-κB p65 in the pathway for NF-κB activation and by enhancing ABCG1-dependent lipid transportation. Therefore, an LXR agonist is a promising therapeutic candidate for AMD, especially for wet AMD. [ABSTRACT FROM AUTHOR]

Background: Chasmogamous (CH)–cleistogamous (CL) dimorphic flowers are developed in Viola prionantha. However, the environmental and genetic factors necessary for the CH–CL transition are unknown. Results: In the present work, short-day (SD) conditions induced CH flowers, whereas long days (LDs) triggered CL flowers in V. prionantha. Compared to fully developed CH flowers, CL flowers had less mature stamens, no nectar glands, and immature petals. Comparative transcriptomics revealed differentially expressed genes (DEGs) during CL and CH development. Core genes in the photoperiod pathway, such as V. prionantha orthologs of GIGANTEA (GI), CONSTANS (CO), and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1), which promote floral induction, were highly expressed in CL flowers, whereas UNUSUAL FLORAL ORGANS (UFO) and B-class MADS-box genes for floral organ identity and development showed an opposite alteration. Moreover, genes in the glycolytic process, sucrose metabolic process, and fatty acid biosynthetic process were all highly expressed in CH flowers. Interestingly, V. prionantha orthologs of the B-class MADS-box genes APETALA3 (AP3) and PISTILLATA (PI) might relate to these sugar–fatty acid processes and were co-expressed with GAIP-B-like and YABBY5 (YAB5), which regulate the development of the petal, stamen, and nectary. Compared to CH flowers, DEGs and hub genes in the most significantly correlated modules of the gene co-expression network, which are involved in abiotic and biotic responses, were upregulated in CL flowers. Conclusions: We proposed an integrative model for transcription regulation of genes in the photoperiod pathway, floral organ development, stress response, and sugar–fatty acid processes to determine CH–CL flower development in V. prionantha. Particularly, under LDs, activated GI may induce genes involved in the stress-response pathways, and then downregulated AP3 and PI or UFO to inhibit the sugar–fatty acid metabolic processes, together forming CL flowers. In contrast, CH flowers were produced under SDs. This work provides novel insights into the developmental evolution of dimorphic flowers in Viola. [ABSTRACT FROM AUTHOR]

In the process of yielding biofuels from cellulose degradation, traditional enzymatic hydrolysis, such as β-glucosidase catalyzing cellobiose, can barely resolve the contradiction between cellulose degradation and bioenergy conservation. However, it has been shown that cellobiose phosphorylase provides energetic advantages for cellobiose degradation through a phosphorolytic pathway, which has attracted wide attention. Here, the cellobiose phosphorylase gene from Caldicellulosiruptor bescii (CbCBP) was cloned, expressed, and purified. Analysis of the enzymatic properties and kinetic mechanisms indicated that CbCBP catalyzed reversible phosphorolysis and had good thermal stability and broad substrate selectivity. In addition, the phosphorolytic reaction of cellobiose by CbCBP proceeded via an ordered Bi Bi mechanism, while the synthetic reaction proceeded via a ping pong Bi Bi mechanism. The present study lays the foundation for optimizing the degradation of cellulose and the synthesis of functional oligosaccharides. [ABSTRACT FROM AUTHOR]

We aim to determine the correlation between parental rearing, personality traits, and obsessive–compulsive disorder (OCD) in different quantiles. In particular, we created an intermediary effect model in which parental rearing affects OCD through personality traits. All predictors were measured at the time of the survey, comprising parental rearing (paternal rearing and maternal rearing), demographics (grade and gender), and personality traits (neuroticism, extroversion, and psychoticism). These results suggest that (a) paternal emotional warmth was negatively correlated with OCD at the 0.40–0.80 quantile, while maternal emotional warmth was positively correlated with the OCD at the 0.45–0.69 quantile. (b) The correlation between negative parental rearing and OCD ranged from the 0.67 to 0.95 quantile for paternal punishment, 0.14–0.82 quantile for paternal overprotection, 0.05–0.36 and >0.50 quantile for maternal over-intervention and overprotection, and 0.08–0.88 quantile for maternal rejection. (c) Extroversion, neuroticism, and psychoticism were not only associated with OCD in a particular quantile but also mediated between parental rearing (namely parental emotional warmth, paternal punishment, paternal overprotection, maternal rejection, maternal over-intervention, and overprotection) and OCD. These findings provide targets for early interventions of OCD to improve the form of family education and personality traits and warrant validation. [ABSTRACT FROM AUTHOR]

• A Novel mouse model of USH developed using KM and CBA/J mice. • KMush/ush mice exhibit an USH phenotype based on various assessment tools. • A new mouse model contains Adgrv1 mutations and can be used for audiological research. Previously, we discovered a strain of Kunming mice, referred to as the KMush/ush strain, that exhibited notably abnormal electroretinogram (ERG) readings and elevated thresholds for auditory brainstem responses (ABRs), which resembled the characteristics of Usher Syndrome (USH). We successfully identified the pathogenic genes, Pde6b and Adgrv1 , after KMush/ush crossbred with CBA/CaJ mice, referred to as CBA-1ush/ush, CBA-2ush/ush or CBA-2ush/ush. In this investigation, we crossbred KMush/ush and CBA/J mice to establish novel recombinant inbred lines and analysed their phenotypic and genotypic characteristics. ERG readings, ABR testing, fundus morphology, histological examination of the retina and inner ear, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis, western blotting, DNA sequence analysis and behavioural experiments were performed to assess the phenotypes and genotypes of the progeny lines. No obvious waveforms in the ERG were detected in F1 hybrid mice while normal ABR results were recorded. The F2 hybrids, which were called J1ush/ush or J2ush/ush, exhibited segregated hearing-loss phenotypes. J1ush/ush mice had a retinitis pigmentosa (RP) phenotype with elevated ABR thresholds, whereas J2ush/ush mice exhibited only the RP phenotype. Interestingly, J1ush/ush mice showed significantly higher ABR thresholds than wild-type mice at 28 days post born (P28), and RT-qPCR and DNA-sequencing analysis showed that Adgrv1 gene expression was significantly altered in J1ush/ush mice, but histological analysis showed no significant structural changes in the organ of Corti or spiral ganglia. Further elevation of ABR-related hearing thresholds by P56 manifested only as a reduced density of spiral ganglion cells, which differed significantly from the previous pattern of cochlear alterations in CBA-2ush/ush mice. We successfully introduced the hearing-loss phenotype of inbred mice with USH into CBA/J mice, which provides a good animal model for future studies on the important physiological roles of the Adgrv1 gene in inner-ear structure and for therapeutic studies targeting Adgrv1 -mutated USH. [ABSTRACT FROM AUTHOR]

Abstract: Oxidative stress is associated with insulin resistance (IR) and is thought to contribute to the development and progression toward type 2 diabetes (T2DM). This study was undertaken to isolate the bioactive polysaccharide (SMPW1) from Salvia miltiorrhiza Bunge and investigated its protective effects on IR model in rats induced by tert-butyl hydroperoxide (t-BHP). In vivo animal experiments showed that SMPW1 (50 and 100mg/kg) possessed high antioxidative and protective capacity against the injury induced by t-BHP, as reflected in the increased expression or activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and the decreased formation of malondialdehyde (MDA) in serum and liver homogenates. In addition, SMPW1 (50 and 100mg/kg) also attenuated IR and the morphological injury of liver and pancreas induced by t-BHP, and improved insulin sensitivity index. In conclusion, SMPW1 can protect against the development of T2DM and improve IR via reduction of oxidative stress. [Copyright &y& Elsevier]

Abstract: In this paper, it was found that Laccase (Lac) could be stably immobilized on the glassy carbon electrode modified with Black Pearl 2000 (BP2000) and Nafion by a simple technique. The adsorption behavior of Lac immobilized on BP2000 matrix was characterized by environment scanning electron microscope (ESEM), ultraviolet–visible (UV–vis) and Fourier transform infrared (FTIR), which demonstrated that BP2000 could facilitate the electron exchange between the active center of Lac and modified electrode. The direct electrochemistry and electrocatalysis behavior of Lac on the modified electrode were characterized by cyclic voltammogram (CV) which indicated that Lac immobilized on the modified electrode displayed a direct, nearly reversible and surface-controlled redox reaction with an enhanced electron-transfer rate constant of 1.940s−1 at the scan rate of 100mVs−1 in 0.1M phosphate buffer solution (PBS) (pH 7.0). Furthermore, it was also discovered that, in the presence of O2, Lac immobilized on the modified electrode exhibited the electrocatalytic response to pyrocatechol, and the kinetic apparent Michaelis-constant () obtained from the Lineweaver–Burk equation was 1.79mM. The detection limit, linear range and sensitivity of the Lac biosensor were 0.003mM, 0.003–5.555mM and 99.84μAmM−1 cm−2, respectively. [Copyright &y& Elsevier]

Abstract: Ordered MCM-41-type mesoporous silica nanoparticles (MSNs) with pore size of 2.6nm were synthesized and were further modified with various amounts of 3-aminopropyltriethoxysilane (APTES), respectively, by a direct co-condensation method. These amine functionalized mesoporous silica nanoparticles (Am-MSNs) were employed to complex with plasmid DNA (pDNA) to study their adsorption and protection capacities. The results demonstrate the MSNs functionalized with aminopropyl groups present advanced adsorption capacities for pDNA immobilization. And Am-MSNs with high APTES amount lead to high amount of pDNA adsorption. Further investigation of pDNA protection shows that Am-MSNs with moderate APTES amount could completely protect pDNA from enzymatic degradation, while those with smaller and/or higher amount of APTES could partially provide protection of pDNA. [Copyright &y& Elsevier]

Abstract: The thermophilic lipase QLM-catalyzed resolution of (R, S)-2-octanol and (R, S)-2-pentanol via transesterification was carried out in various organic solvents, and the solvent effects on the enzyme''s enantioselectivity were investigated. A significant negative correlation between the enantiomeric ratio, E, and the size of the solvent molecules was observed. The highest E value, 21, was obtained in the small molecular-sized solvent dichloromethane when (R, S)-2-octanol was resolved with vinyl acetate as acyl donor. Thermodynamic analysis indicated that the difference in activation free energy between the two enantiomers was about 25.5% lower in dichloromethane than in the solvent-free system, and the change in the difference in activation entropy between the enantiomers was the main contributor to the changes in E values with the molecular size of solvents. [Copyright &y& Elsevier]

Glutamate dehydrogenase from Pyrococcus horikoshii (Pho-GDH) was cloned and overexpressed in Escherichia coli. The cloned enzyme with His-tag was purified to homogeneity by affinity chromatography and shown to be a hexamer enzyme of 290±8 kDa (subunit mass 48 kDa). Its optimal pH and temperature were 7.6 and 90 °C, respectively. The purified enzyme has outstanding thermostability (the half-life for thermal inactivation at 100 °C was 4 h). The enzyme shows strict specificity for 2-oxoglutarate and l-glutamate and requires NAD(P)H and NADP as cofactors but it does not reveal activity on NAD as cofactor. Km values of the recombinant enzyme are comparable for both substrates: 0.2 mM for l-glutamate and 0.53 mM for 2-oxoglutarate. The enzyme was activated by heating at 80 °C for 1 h, which was accompanied by the formation of its active conformation. Circular dichroism and fluorescence spectra show that the active conformation is heat-inducible and time-dependent. [Copyright &y& Elsevier]

Background/Aims: Our laboratory discovered a Kunming mouse with enormous electroretinogram (ERG) defects. Its auditory brainstem response (ABR) threshold was significantly elevated and closely resembled the features of Usher syndrome (USH). This study sought to cross these USH-like mice (named KMush/ush mice) with CBA/CaJ mice to establish recombinant inbred strains and identify their phenotypes and genotypes. Methods: KMush/ush mice were crossed with CBA/CaJ mice to establish inbred strains by sibling mating. ERG, ABR, ocular fundus morphology, histological examinations of the retina and inner ear, quantitative real-time polymerase chain reaction, western blotting, and exon sequencing were performed to assess the phenotypes and genotypes of the offspring strains. Results: The F1 hybrids from crossing KMush/ush and CBA/CaJ mice had normal ERG and ABR responses. The F2 offspring from intercrossing the F1 mice showed a segregation of the retinitis pigmentosa (RP) and hearing loss phenotypes. The CBA-1ush/ush mice had an RP phenotype that was characterized by a vanished ERG waveform and loss of the outer nuclear layer. Their Pde6b gene had a nonsense mutation that resulted in the failure of protein production in western blotting. However, the ABR threshold of this strain of mice was normal. The CBA-2ush/ush mice had normal retinal function and architecture. Their ABR threshold was increased, with a dramatic degeneration of the stereocilia bundles in the outer hair cells of the inner ear. Whole exome sequencing and exon sequencing revealed a deletion of one base pair in exon 31 of the Adgrv1 gene, which would result in the premature termination of protein encoding. The level of Adgrv1 mRNA was reduced in the CBA-2ush/ush mice. The CBA-3ush/ush mice had phenotypes of RP, elevated ABR threshold, and degeneration of the stereocilia bundles in the outer hair cells. They were closely associated with the nonsense mutations of Pde6b and Adgrv1, respectively. Conclusion: We isolated a mouse strain with hearing loss from inbred mice with retinal degeneration and established it as a recombinant inbred strain with a spontaneous mutation in Adgrv1, the human Usher syndrome 2C gene. The retinal degeneration was cause by a mutation in Pde6b, while the hearing loss was caused by a mutation in Adgrv1. [ABSTRACT FROM AUTHOR]

Cellulases play key roles in the degradation of lignocellulosic materials. The function and mechanism of the catalytic domain (CD) and carbohydrate-binding module (CBM) of cellulases were earlier revealed by analysis and characterization of protein structure. However, understanding of the catalytic mechanism of the entire enzyme, and the analysis of the catalytic model, were inadequate. Therefore, the linker chain between CD and CBM has been extensively studied to bridge this gap. Cellulase AcCel12B and three mutants with different linker lengths (with no or 1-3 PT/S-box units) were successfully constructed and purified. Results showed that the activity of cellulases on Avicel and regenerated amorphous cellulose (RAC) increased with the number of PT/S-box units. Furthermore, the desorption of AcCel12B and its mutants from RAC and Avicel were significantly different. The energy of desorption of wild-type and mutant AcCel12B from cellulose decreased with the number of PT/S-box units. Thus, AcCel12B containing more PT/S-box units was more easily desorbed and had more opportunity to hydrolyze cellulose than other samples. The number of PT/S-box units in endocellulase affected the desorption of the enzyme, which is possibly responsible for the differences in the activity of wild-type and mutant AcCel12B on Avicel and RAC. [ABSTRACT FROM AUTHOR]

We occasionally discovered a mouse with spontaneous retinitis pigmentosa (RP) from Kunming (KM) mouse breeding colony, with no obvious waveforms in ERG recordings. The aim of this study is to cross the spontaneously hereditary retinal degeneration mice (temporarily designated as KM/rd mice) derived from KM mice with C57BL/6J mice to establish a congenic inbred strain (temporarily designated as the B6/rd mice), and study the ocular phenotype and genotype of the mice. Fundus photography, tissue morphology, electroretinography (ERG), qRT-PCR, western blot and DNA sequence analysis were performed to observe the ocular phenotype and genotype of KM/rd and B6/rd mice. The fundus photography showed progressive retinal vascular degeneration and depigmentation in KM/rd and B6/rd mice. Compared to wild-type mice, the histological analysis revealed that the outer nuclear layer of the mutated mice was significantly reduced at 14 days post born (P14), and almost disappeared by P21. No obvious waveforms were detected at P14 and P21 in the ERG from KM/rd and B6/rd mice. qRT-PCR results showed that the expression quantities of mRNA of pde6b gene in KM/rd and B6/rd mice were significantly lower compared with those of wild-type controls at P21. Western blot results confirmed an abnormal protein expression of pde6b gene in KM/rd and B6/rd mice with no protein products, while there was an obvious protein expression in wild-type mice. The nonsense mutation in exon 7 (a mutation that changes the codon 347 from TAC to TAA) in the pde6b gene of KM/rd and B6/rd mice was identified by genomic DNA sequence analysis. All these findings revealed that the ocular phenotype and genotype of KM/rd and B6/rd mice were similar to those of rd1 mice, which indicates that KM/rd and B6/rd mice can be used as an RP mouse model. [ABSTRACT FROM AUTHOR]

In the present study, two novel peptides Lys-Trp-Phe-Cys-Thr (KWFCT) and Gln-Trp-Phe-Cys-Thr (QWFCT) were purified and identified from 3 to 10 kDa pine nut ( Pinus koraiensis ) meal protein. Their cytotoxicity and antioxidant activities in vitro were determined. Additionally, pulsed electric field technology, antioxidant activities, and circular dichroism were used together to investigate the relationship between antioxidant activities and secondary structure. The results showed that neither peptide demonstrated cytotoxicity in HepG2 cells. KWFCT had higher values for 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition (67.43% ± 1.33%) and ferric-reducing antioxidant power (67.86 ± 1.03 mM Fe 2+ /mg), and Ac-QWFCT had higher values for 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) inhibition (74.9% ± 1.19%) and cellular antioxidant activity (916.32 μmol of QE/100g) ( P < 0.05). The antioxidant activities reached their highest values when parameters of PEF were 5 kV/cm and 2400 Hz. An increase in antioxidant activities of Ac-QWFCT was correlated with a decrease in random coil content. [ABSTRACT FROM AUTHOR]

The N-methyl-N-nitrosourea (MNU)-treated rat is typically used as an animal model of chemically-induced retinitis pigmentosa (RP). Reactive oxygen species (ROS) have been recognized as the crucial contributor to the retinal photoreceptor apoptosis seen in MNU-treated rats. In the present study, we explored the therapeutic effects of hydrogen-rich saline (HRS), a selective ROS scavenger, on MNU-induced photoreceptor degeneration. Intraperitoneal (IP) administration of HRS ameliorated MNU-induced photoreceptor degeneration in terms of morphology and function: Sharply decreased thickness of the retinal outer nuclear layer (ONL) and flattened photopic and scotopic electroretinogram (ERG) waveforms, typically seen in response to MNU treatment, were substantially rescued in rats cotreated with MNU and HRS (MNU + HRS). Moreover, the terminal deoxyuridine triphosphate nick-end labeling (TUNEL) assay revealed a smaller number of apoptotic photoreceptors in the MNU + HRS group compared that in the MNU group. Compared to MNU-treated rats, retinal malondialdehyde (MDA) content in MNU + HRS rats significantly decreased while superoxide dismutase (SOD) activity significantly increased. Morphological and multi-electrode array (MEA) analyses revealed more efficient preservation of the architecture and field potential waveforms in particularly the peripheral regions of the retinas within the MNU + HRS group, compared to that in the MNU group. However, this enhanced protection of structure and function in the peripheral retina is unlikely the result of site-dependent variation in the efficacy of HRS; rather, it is most likely due to reduced susceptibility of peripheral photoreceptors to MNU-induced degeneration. Inner retinal neuron function in the MNU + HRS rats was better preserved, with fewer apoptotic photoreceptors in the ONL. Collectively, these results support the rationale for future clinical evaluation of HRS as a therapeutic agent for human RP. [ABSTRACT FROM AUTHOR]

Purpose: Our purpose was to explore pupil light response (PLR) with respect to the change in sensitivity of photoreceptors during various dark adaptation phases and to determine the optimal duration of dark adaptation time before the PLR. Methods: The PLR was recorded in 15 healthy subjects and three patients with neural or retinal vision loss after 1-sec blue and red light stimuli of 1, 10, and 100 cd/m. The PLR was repeated nine times at different checkpoints during the 40-minute dark adaptation. The transient contraction amplitude, sustained contraction amplitude, and relative sustained contraction ratio of the PLR were analyzed. Results: The increase in the transient contraction amplitude during the entire dark adaptation process was significant (changing up to 45.1 %) in the initial phase of dark adaptation under different stimulus conditions. The changes in the sustained contraction amplitude and the relative sustained contraction ratio were substantial (changing up to 71.0 % and 37.2 % from 1 to 20 minutes of dark adaptation, respectively) under high-intensity blue illumination. The inflection point of the contraction curves in the dark adaptation was 15 or 20 minutes. The patients' PLR results changed in a similar manner. Conclusions: The changes in the sensitivity of different photoreceptors occurred at different rates, and the contraction amplitude of the PLR was significantly affected by the dark adaptation duration. So 20 minutes of dark adaptation before PLR testing was suggested to achieve a consistent and stable pupil response. The dark adaptation effect should be put into consideration when comparing the results from different phases of the PLR test. [ABSTRACT FROM AUTHOR]

The CACNA1F gene encodes a member of the alpha-1F subunit family in the voltage-dependent calcium channel (Cav1.4) complex. Mutations in this gene result in incomplete congenital stationary night blindness (iCSNB2) in humans. And Cav1.4 mutation could affect the functions of the skeletal muscle. This study investigated the role of Cacna1f mutations in alteration of the skeletal muscle functions in a Cacna1f mutation rat model ( Cacna1f CSNB2 rat). We found that the muscle endurance behaviors of Cacna1f CSNB2 rats were significantly lower than those of the wild-type rats. The high-frequency fatigue resistance of the soleus muscle was decreased in Cacna1f CSNB2 rats under continuous tetanic stimulation. The expression levels of the syntaxin (SYN) proteins in the soleus of the Cacna1f CSNB2 rats were lower than those of wild-type rats. SYN was expressed in the soleus muscle, but not in the extensor digitorum longus. The Ca v 1.4 protein was not detected in the skeletal muscle of Cacna1f CSNB2 rats. The Cacna1f mRNA level in the soleus of Cacna1f CSNB2 rats was decreased compared with that in wild-type rats. This study demonstrated for the first time that the Cacna1f mutation reduces the function of slow-twitch skeletal muscle. And it also demonstrated that the Cacna1f gene affects synapse-associated protein expression, which may block the signal transmission in synaptic connectivity of the retina and skeletal muscle in Cacna1f -mutant rats. [ABSTRACT FROM AUTHOR]

Abstract: Background: Studies have shown that inhalation of hydrogen gas, which acts as an antioxidant, can protect the brain against free radicals in rats with ischemia-reperfusion. The neuronal damage caused by acute carbon monoxide (CO) poisoning is partly free radical mediated. We hypothesize that hydrogen may prevent neurological damage from CO poisoning. Objectives: This study is designed to test whether hydrogen (H2)-rich saline will have a protective effect on rats with acute CO poisoning. Methods: Male Sprague-Dawley rats were subjected to CO poisoning. H2-rich saline was administered by peritoneal injection (6mL/kg/24h). We used the Morris water maze and the open field test to determine cognitive function. After cognitive function studies, rats were decapitated and the levels of trace elements copper (Cu), zinc (Zn), and iron (Fe) in serum and brain were assessed by flame atomic absorption spectrometry. Necrosis, apoptosis, and autophagy of neurons were assessed by H-E staining and immunohistochemical staining in another group of rats. Results: H2-rich saline treatment improved the cognitive deficits and reduced the degree of necrosis, apoptosis, and cell autophagy in rats. Additionally, H2-rich saline decreased the content of Fe in serum and brain in these rats, and increased the content of serum Cu related to free radical metabolism. Conclusions: H2-rich saline may effectively protect the brain from injury after acute CO poisoning. The mechanism of this protection may be related to lessening oxidative damage by affecting trace elements in vivo. [Copyright &y& Elsevier]

Abstract: Organophosphorus compounds (OPs) are widely used as pesticides because of their ability to inhibit the activity of acetylcholinesterase (AChE) in the nervous system. Thus, AChE is generally used as a biosensor for pesticide detection. Due to the instability of AChE a more stable enzyme would be desirable for robust applications. We investigated the sensitivity of a thermostable carboxylesterase from the archaeon Archaeoglobus fulgidus (AFEST) to seven selected OPs. The IC50 of dichlorvos against AFEST (50.8±2.6nM) was 10-fold lower than that of the commercially obtained AChE, indicating that AFEST had higher sensitivity. Its sensitivity for the other OPs was lower than AChE. To enhance the sensitivity of AFEST to OPs, site-directed mutations were introduced in the cap domain of AFEST. The sensitivity of mutant N44S/S48V was enhanced toward all seven OPs compared to the wild-type and was higher than AChE for four OPs, including paraoxon (3.3±0.01nM), dichlorvos (28.0±0.6nM), profenofos (43.0±1.0nM), and diazinon (3.0±0.2nM). The half-lives of AFEST and the mutant N44S/S48V at 37°C were over 15 d. The interactions between the enzymes and select OPs were investigated by molecular docking. The results demonstrated that AFEST and the mutant N44S/S48V have the potential to be biosensor for OP detection. [Copyright &y& Elsevier]

Motion sickness presents a challenge due to its high incidence and unknown pathogenesis although it is a known fact that a functioning vestibular system is essential for the perception of motion sickness. Recent studies show that the efferent vestibular neurons contain calcitonin gene-related peptide (CGRP). It is a possibility that the CGRP immunoreactivity (CGRPi) fibers of the efferent vestibular system modulate primary afferent input into the central nervous system; thus, making it likely that CGRP plays a key role in motion sickness. To elucidate the relationship between motion sickness and CGRP, the effects of CGRP on the vestibular efferent nucleus and the vestibular nucleus were investigated in rats with motion sickness. Methods: An animal model of motion sickness was created by subjecting rats to rotary stimulation for 30 minutes via a trapezoidal stimulation pattern. The number of CGRPi neurons in the vestibular efferent nucleus at the level of the facial nerve genu and the expression level of CGRPi in the vestibular nucleus of rats were measured. Using the ABC method of immunohistochemistry technique, measurements were taken before and after rotary stimulation. The effects of anisodamine on the expression of CGRP in the vestibular efferent nucleus and the vestibular nucleus of rats with motion sickness were also investigated. Results and Discussion: Both the number of CGRPi neurons in the vestibular efferent nucleus and expression level in the vestibular nucleus increased significantly in rats with motion sickness compared to that of controls. The increase of CGRP expression in rats subjected to rotary stimulation 3 times was greater than those having only one-time stimulation. Administration of anisodamine decreased the expression of CGRP within the vestibular efferent nucleus and the vestibular nucleus in rats subjected to rotary stimulation. In conclusion, CGRP possibly plays a role in motion sickness and its mechanism merits further investigation. [ABSTRACT FROM AUTHOR]

Cacna1f gene mutation could lead to incomplete congenital stationary night blindness (iCSNB) disease. The CSNB-like phenotype rat is a spontaneous rat model caused by Cacna1f gene mutation. The present study explored the phenotypic properties of behavior performance in CSNB rats further. The vision-related behaviors of CSNB rats were assessed with a Morris water maze (MWM), passive avoidance tests, and open-field test. Motor ability was evaluated with a rotarod test and a wire hang test, and mechanical pain and thermalgia were used to evaluate sensory system function. Electroretinograms (ERGs) were recorded to evaluate the function of the retina. The vision-related results showed that longer latencies of escape and reduced probe trial in MWM for CSNB rats. There were more errors in avoidance test; CSNB rats were more active in the open field and presented a different pattern of exploration. The locomotor-related behaviors showed shorter falling latencies in the rotarod test and shorter gripping time in CSNB rats. And mechanical thresholds of pain increased in CSNB rats. The ERGs indicated that both the amplitude and latency of rod and cone systems were impaired in the CSNB rats. In summary, Cacna1f gene mutation changed the performance of various behaviors in the CSNB rat aside from vision-related phenotype. Cacna1f gene might play a role in a wide range of responses in the organism. These results confirm the importance of a comprehensive profile for understanding the behavior phenotype of Cacna1f gene mutation in CSNB rat. [ABSTRACT FROM AUTHOR]

Abstract: This work was conducted to determine whether congenital stationary night blindness (CSNB), which is caused by a Cacna1f mutation, could affect development of second-order neurons in the retina, such as horizontal cells (HCs). The CSNB rats and age-matched wild type rats were sacrificed at postnatal days (PND) 15, 30 and 60. Morphometric analyses of HCs, which were labeled by a primary antibody to calbindin D-28K, were performed at the light microscopic level on retinal cross sections and whole mount retinas. Calbindin D-28K was measured by western blotting in retinal samples. We found that the average number and density of HCs, Calbindin level and thickness of OPL were all decreased significantly in CSNB group compared to control group. These results indicated that second-order retinal neurons, such as horizontal cells, are affected by retinal degeneration. The relationship between the absence of HCs and the gene defect of CSNB requires further research. [Copyright &y& Elsevier]

Purpose: The aim of this study was to assess the changes in the prevalence of visual impairment due to blinding trachoma in Sichuan, China between 1987 and 2006. Methods: Over 125,000 residents of Sichuan province participated in the National Sample Survey on Disabilities, conducted in both 1987 and 2006. Changes in the prevalence of visual impairment due to blinding trachoma were analyzed while accounting for other factors including gender, age and residence (urban vs. rural). Results: In 1987, blinding trachoma ranked second among the eight major visual impairment causes assessed with a prevalence of 172.9 (95% CI: 152.2-196.6) per 100,000, while in 2006 it ranked eighth with a prevalence of 58.1 (95% CI: 45.5-73.0) per 100,000. The prevalence in 2006 decreased significantly compared to 1987 in both rural and urban areas, as well as in both genders. Furthermore, in both 1987 and 2006, visual impairment due to blinding trachoma tended to be concentrated among individuals over 40, although it was also seen in young people. Conclusion: In the past 20 years, the prevalence and percentage of visual impairment due to blinding trachoma was significantly reduced in Sichuan province, and we anticipate a further decrease in the future. [ABSTRACT FROM AUTHOR]

Abstract: This paper discussed the use of a recombinant Escherichia coli whole-cell biocatalyst harboring a thermophilic lipase gene from Fervidobacterium nodosum in the catalytic synthesis of polyesters. The ring-opening polymerization of ɛ-caprolactone was used as a model reaction to study the effects of temperature and reaction medium on monomer conversion and the molecular weight of the product. The whole-cell biocatalyst displayed high catalytic activity at high temperatures (70–90°C), with almost 100% monomer conversion. Meanwhile, high monomer conversion values (>97%) were achieved in both hydrophobic and hydrophilic solvents, with the exception of dichloromethane (85%). Poly(ɛ-caprolactone) was obtained in 100% monomer conversion, with a number-average molecular weight of 2000g/mol and a polydispersity index of 1.47 in cyclohexane at 70°C for 72h. Furthermore, the whole-cell biocatalyst exhibited excellent operational stability, with monomer conversion values exceeding 90% over the course of 10 batch reactions. To verify the practicality of the procedure, scale-up reaction was also performed with isolated yield and number-average molecular weight of ca. 70% and 2140g/mol, respectively. [Copyright &y& Elsevier]

Abstract: The paper explored the catalytic activity of a novel thermophilic lipase from Fervidobacterium nodosum for polyester synthesis, using the ring-opening polymerization of ɛ-caprolactone as the model. Effects of enzyme concentration, reaction medium, temperature and reaction time on monomer conversion, product molecular weight and distribution were systematically investigated. Remarkably, the enzyme could be effectively performed at high temperatures, and showed the highest activity towards the polymerization of ɛ-caprolactone at 90°C. Through the optimization of reaction conditions, poly(ɛ-caprolactone) was obtained in almost 100% monomer conversion, with a number-average molecular weight of 2340g/mol and a polydispersity index of 1.34 in toluene at 90°C for 72h. Michaelis–Menten kinetic analysis indicated that compared with Candida antarctica lipase B, the enzyme had higher affinity for ɛ-caprolactone with a K m value of 0.35mol/L. Furthermore, the possible structural and energetic basis of the interaction of enzyme and the monomer ɛ-caprolactone was elucidated using molecular docking. [ABSTRACT FROM AUTHOR]

Abstract: The disease-causing gene which underlies a naturally occurring X-linked mutant cone dysfunction Sprague–Dawley rat model was investigated. Full-field electroretinogram (ERG) and simple sequence length polymorphism analyses were applied to 441-second filial generation rats that were derived from crossing a mutant rat and a Brown–Norway rat. After identifying a mutation mapping within the telomeric region of chromosome X, a candidate gene related to retinal cone function in this region was further screened using real-time PCR, immunohistochemistry and histological methods. The results showed that a G-to-T substitution at the splice acceptor site of intron 4 was present in the opsin 1, medium-wave sensitive (Opn1mw) gene, thereby causing down-regulated transcription and translation. These changes were consistent with abnormities seen in the ERG response. However, there was no significant histological change in the mutant rat retina. Therefore, we infer from this that the causative gene for the mutation is Opn1mw and consequently term this a middle-wavelength opsin cone dysfunction (MCD) rat model. The deficiency in vision of the MCD rat is similar to the color vision defects that occur in humans with a color vision defect but without recessive retinal degeneration. This rat model may be useful for understanding the mechanism that is responsible for color vision and for developing clinical therapies for several retinal dystrophies caused by cone opsin deficiencies. [Copyright &y& Elsevier]

Abstract: The ring-opening polymerization of ɛ-caprolactone catalyzed by a novel thermophilic esterase from the archaeon Archaeoglobus fulgidus was successfully conducted in organic solvents. The effects of enzyme concentration, temperature, reaction time, reaction medium, and water activity on monomer conversion and product molecular weight were investigated. Poly(ɛ-caprolactone) was obtained in almost 100% of the monomer conversion, with a number-average molecular weight of 1400 in toluene at 80°C for 72h. Furthermore, the Michaelis–Menten kinetic analysis showed that the enzyme had the highest affinity for ɛ-caprolactone, with a K m value of 0.093mol/l compared with other reported lipases. The possible structural and energetic effects of the enzyme on the K m value were investigated, using molecular docking studies. [Copyright &y& Elsevier]

Abstract: With succinic anhydride as acylating agent, three commercial lipases –Candida antarctica lipase B (CALB), Pseudomonas cepacia lipase and Pseudomonas fluorescens lipase – were employed in the kinetic resolution of a series of rac-alkyl alcohols: 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-methyl-2-butanol, 6-methyl-5-heptene-2-ol, 3-methyl-2-cyclohexene-1-ol and 2-methyl-1-pentanol. The most effective tested enzyme, immobilized CALB, was able to resolve most of the alcohols with high enantioselectivity, even higher (with enantiomeric ratios up to 115 and 91, for 3-hexanol and 3-methyl-2-butanol, respectively) than when vinyl acetate was used as the acylating agent. More importantly, the unreacted alcohol and the monoester succinate produced could be easily separated by a simple aqueous base-organic solvent liquid–liquid extraction. Using succinic anhydride as acylating agent and CALB, enantiomerically pure (S)-2-pentanol with 99% ee and (R)-2-pentanol with 95% ee were prepared in gram-scale reactions. [Copyright &y& Elsevier]

Abstract: Acylpeptide hydrolase of Aeropyrum pernix K1 is composed of a catalytic α/β hydrolase domain and a non-catalytic β-propeller domain. The Glu88 residue of the propeller domain is highly conserved in the prolyl oligopeptidase family and forms an inter-domain salt bridge with Arg526, a key residue for substrate binding. We have dissected the functions of Glu88 using site-directed mutagenesis, steady-state kinetics analyses, and molecular dynamics simulations. In E88A and E88A/R526K mutants, with a broken inter-domain salt bridge and a positive charge at position 526, catalytic activities for both a peptidase substrate and an esterase substrate were almost abolished. Analysis of the pH dependence of the mutants'' reaction kinetics indicates that these mutations lead to changes in the electrostatic environment of the active site, which can be modulated by chloride ions. These findings indicate that the neutralization at position 526 is favorable for the activity of the enzyme, which is also verified by the catalytic behavior of E88A/R526V mutant. All mutants have lower thermodynamic stability than the wild-type. Therefore, Glu88 plays two major roles in the function of the enzyme: neutralizing the positive charge of Arg526, thereby increasing the enzymatic activity, and forming the Glu88–Arg526 salt bridge, thereby stabilizing the protein. [Copyright &y& Elsevier]

Focuses on the study of gene function via manipulation of mouse genome. The high homology between human and mouse genomes that allows a disease model to be formed; Use of a chemical mutagen ethylnitrosourea (ENU) to create germ cell mutations in male mice; Screening of the first generation of mutated mice for abnormal phenotypes on gross morphology, behavior, learning and memory, auditory brainstem response (ABR), electrocardiogram (ECG), electroetinogram (ERG), flash-visual evoked potential F-VEP), home mineral density, and blood sugar level; Number of mice with specific dominant abnormalities; High frequency of fur color changes, eye defects and hearing loss; Finding that abnormalities related to metabolism are least frequent; Sex preference observed in mice; Suggestion that behavior abnormalities of G1 mice are not inheritable because of multi-gene control; Implications of the research for cloning disease-related genes.

With the development of China's electric power, power electronics devices such as insulated-gate bipolar transistors (IGBTs) have been widely used in the field of high voltages and large currents. However, the currents in these power electronic devices are transient. For example, the uneven currents and internal chip currents overshoot, which may occur when turning on and off, and could have a great impact on the device. In order to study the reliability of these power electronics devices, this paper proposes a miniature printed circuit board (PCB) Rogowski coil that measures the current of these power electronics devices without changing their internal structures, which provides a reference for the subsequent reliability of their designs. [ABSTRACT FROM AUTHOR]

The aminotransferase from Bacillus circulans (BtrR), which is involved in the biosynthesis of butirosin, catalyzes the pyridoxal phosphate (PLP)-dependent transamination reaction to convert valienone to β-valienamine (a new β-glycosidase inhibitor for the treatment of lysosomal storage diseases) with an optical purity enantiomeric excess value. To explore the stereoselective mechanism of valienamine generated by BtrR, multiple molecular dynamics (MD) simulations were performed for the BtrR/PLP/valienamine and BtrR/PLP/β-valienamine complexes. The theoretical results showed that β-valienamine could make BtrR more stable and dense than valienamine. β-valienamine could increase the hydrogen bond probability and decrease the binding free energy between coenzyme PLP and BtrR by regulating the protein structure of BtrR, which was conducive to the catalytic reaction. β-valienamine maintained the formation of cation-p interactions between basic and aromatic amino acids in BtrR, thus enhancing its stability and catalytic activity. In addition, CAVER 3.0 analysis revealed that β-valienamine could make the tunnel of BtrR wider and straight, which was propitious to the removal of products from BtrR. Steered MD simulation results showed that valienamine interacted with more residues in the tunnel during dissociation compared with β-valienamine, resulting in the need for a stronger force to be acquired from BtrR. Taken together, BtrR was more inclined to catalyze the substrates to form β-valienamine, either from the point of view of the catalytic reaction or product removal. [ABSTRACT FROM AUTHOR]

Zearalenone hydrolase (ZHD) is the only reported α/β-hydrolase that can detoxify zearalenone (ZEN). ZHD has demonstrated its potential as a treatment for ZEN contamination that will not result in damage to cereal crops. Recent researches have shown that the V153H mutant ZHD increased the specific activity against α-ZOL, but decreased its specific activity to β-ZOL. To understand whyV153H mutation showed catalytic specificity for α-ZOL, four molecular dynamics simulations combining with protein network analysis for wild type ZHD α-ZOL, ZHD β-ZOL, V153H α-ZOL, and V153H β-ZOL complexes were performed using Gromacs software. Our theoretical results indicated that the V153H mutant could cause a conformational switch at the cap domain (residues Gly161–Thr190) to affect the relative position catalytic residue (H242). Protein network analysis illustrated that the V153H mutation enhanced the communication with the whole protein and residues with high betweenness in the four complexes, which were primarily assembled in the cap domain and residues Met241 to Tyr245 regions. In addition, the existence of α-ZOL binding to V153H mutation enlarged the distance from the OAE atom in α-ZOL to the NE2 atom in His242, which prompted the side chain of H242 to the position with catalytic activity, thereby increasing the activity of V153H on the α-ZOL. Furthermore, α-ZOL could easily form a right attack angle and attack distance in the ZHD and α-ZOL complex to guarantee catalytic reaction. The alanine scanning results indicated that modifications of the residues in the cap domain produced significant changes in the binding affinity for α-ZOL and β-ZOL. Our results may provide useful theoretical evidence for the mechanism underlying the catalytic specificity of ZHD. [ABSTRACT FROM AUTHOR]