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Background: Studies have reported that polyphyllin I (PPI) had effective anti-tumor activity against hepatocellular carcinoma (HCC). However, the precise molecular mechanism of this action and the direct target remain unclear. The aim of this study was to discover the molecular targets and the exact mechanism of PPI in the treatment of HCC. Methods: Various HCC cells and Zebrafish xenotransplantation models were used to examine the efficacy of PPI against HCC. A proteome microarray, surface plasmon resonance (SPR) analysis, small molecule transfection, and molecular docking were conducted to confirm the direct binding targets of PPI. Transcriptome and Western blotting were then used to determine the exact responding mechanism. Finally, the anticancer effect and its precise mechanism, as well as the safety of PPI, were verified using a mouse tumor xenograft study. Results: The results demonstrated that PPI had significant anticancer activity against HCC in both in vitro studies of two cells and the zebrafish model. Notably, PPI selectively enhanced the action of the Zinc finger and BTB domain-containing 16 (ZBTB16) protein by directly binding to it. Furthermore, specific knockdown of ZBTB16 markedly attenuated PPI-dependent inhibition of HCC cell proliferation and migration caused by overexpression of the gene. The transcriptome and Western blotting also confirmed that the interaction between ZBTB16 and PPI also activated the PPARγ/RXRα pathway. Finally, the mouse experiments confirmed the efficacy and safety of PPI to treat HCC. Conclusions: Our results indicate that ZBTB16 is a promising drug target for HCC and that PPI as a potent ZBTB16 agonist has potential as a therapeutic agent against HCC by regulating the ZBTB16/PPARγ/RXRα signaling axis. [ABSTRACT FROM AUTHOR]

Outbreaks of hydropericardium hepatitis syndrome caused by fowl adenovirus serotype 4 (FAdV-4) with a novel genotype have been reported in China since 2015, with significant economic losses to the poultry industry. Fiber2 is one of the important structural proteins on FAdV-4 virions. In this study, the C-terminal knob domain of the FAdV-4 Fiber2 protein was expressed and purified, and its trimer structure (PDB ID: 7W83) was determined for the first time. A series of affinity peptides targeting the knob domain of the Fiber2 protein were designed and synthesized on the basis of the crystal structure using computer virtual screening technology. A total of eight peptides were screened using an immunoperoxidase monolayer assay and RT-qPCR, and they exhibited strong binding affinities to the knob domain of the FAdV-4 Fiber2 protein in a surface plasmon resonance assay. Treatment with peptide number 15 (P15; WWHEKE) at different concentrations (10, 25, and 50 μM) significantly reduced the expression level of the Fiber2 protein and the viral titer during FAdV-4 infection. P15 was found to be an optimal peptide with antiviral activity against FAdV-4 in vitro with no cytotoxic effect on LMH cells up to 200 μM. This study led to the identification of a class of affinity peptides designed using computer virtual screening technology that targeted the knob domain of the FAdV-4 Fiber2 protein and may be developed as a novel potential and effective antiviral strategy in the prevention and control of FAdV-4. [ABSTRACT FROM AUTHOR]

Leaves of Strobilanthes cusia Kuntze (S. cusia) are a widely used alexipharmic Traditional Chinese Medicine (TCM) in southern China for the prevention of cold and respiratory tract infectious diseases. One of the most common bacterial pathogens in the respiratory tract is the gram-positive bacterium Streptococcus pneumoniae. The antibiotic resistance of colonized S. pneumoniae makes it a more serious threat to public health. In this study, the leaves of S. cusia were found to perform antibacterial effects on the penicillin-resistant S. pneumoniae (PRSP). Confocal assay and Transmission Electron Microscopy (TEM) monitored the diminished cell wall integrity and capsule thickness of the PRSP with treatment. The following comparative proteomics analysis revealed that the glycometabolism-related pathways were enriched for the differentially expressed proteins between the samples with treatment and the control. To further delve into the specific single effective compound, the bio-active contents of leaves of S. cusia were analyzed by UPLC-UV-ESI-Q-TOF/MS, and 23 compounds were isolated for anti-PRSP screening. Among them, Tryptanthrin demonstrated the most promising effect, and it possibly inhibited the N-glycan degradation proteins, as suggested by reverse docking analysis in silico and further experimental verification by the surface plasmon resonance assay (SPR). Our study provided a research foundation for applications of the leaves of S. cusia as a TCM, and supplied a bio-active compound Tryptanthrin as a candidate drug skeleton for infectious diseases caused by the PRSP. [ABSTRACT FROM AUTHOR]

Methamphetamine (MA) and cocaine (COC) are among the most abused drugs worldwide. In this study, a portable dual-channel surface plasmon resonance (SPR) biosensor based on an indirect inhibitive immunoassay was developed for the rapid and simultaneous determination of MA and COC in saliva. MA-bovine serum albumin (MA-BSA) and COC-BSA conjugates were prepared as antigens and immobilized on the sensor chip in each channel. Upon contact with the surface-immobilized antigens, MA monoclonal antibody (MA-Ab) or COC monoclonal antibody (COC-Ab) enhanced the SPR signal. The bonding of the antibodies to antigens was inhibited by the presence of MA or COC in the samples. The concentrations of the antigens and antibodies were optimized, and the resulting SPR inhibitive immunoassay exhibited good sensitivity, with limits of detection for MA and COC equal to 0.95 and 3.14 ng·mL−1, respectively. These values are below the legal limits of these drugs for vehicle drivers in China. Furthermore, the suitability of the method was confirmed using saliva from healthy donors, which demonstrated acceptable specificities with satisfactory recoveries. The results indicate that the portable SPR biosensor is facile and rapid for the sensitive determination of abused drugs. [ABSTRACT FROM AUTHOR]

The exploration of active ingredients and new activities of industrial crops could expand their scope of applications. Liriodendron chinense (L. chinense), an important ornamental and economic forest tree in China, has been widely used in timber, medicine and landscape. Flavonoids are major constituents of L. chinense leaves, while their effects of preventing brain damage are still unclear. In this study, flavonoids from L. chinense leaves (LCLF) were obtained through AB-8 resin chromatography and UPLC-MS/MS assay indicated that 16 compounds were identified from LCLF. LCLF treatment showed significant scavenging activities against DPPH•, ABTS•+, •OH, FRAP and total reducing power. D-galactose-impaired exploratory behaviors, cognitive functions and histopathological alterations in hippocampus of mice were obviously recovered by LCLF administration. Network pharmacology results demonstrated that LCLF could produce the healing efficacy through multiple pathways, mostly related to oxidative stress and inflammation. Further i n vivo experiments revealed that LCLF treatment could regulated MDA content, SOD, CAT and GSH-Px activity, as well as the production of inflammatory factors (NO, IL-1β and IL-6). The underlying mechanisms of LCLF were probably related to Nrf2/HO-1, NF-κB and AMPK/SIRT1 pathways. Molecular docking results and surface plasmon resonance analysis validated that especially hesperidin in LCLF had strong binding activities with all 8 genes in the mentioned pathways. Our study revealed the beneficial effects of LCLF on oxidative activity and D-galactose-induced brain injury, offering experimental support for its potential application in pharmaceutical and other industries. [Display omitted] • LCLF was a flavonoid-rich fraction from L. chinense leaves. • LCLF showed significant scavenging capacities against different radicals. • LCLF prevented D-galactose-induced brain injuries via AMPK/SIRT1-mediated Nrf2/HO-1 and NF-κB pathways. • Hesperidin in LCLF had strong binding activities with 8 genes in the mentioned pathways. [ABSTRACT FROM AUTHOR]

Huanglian Jiedu Decoction (HJD) is used for treating sepsis in China. Active components from HJD refer to various active ingredients of HJD, while active component formulation (ACF) refers to the combination of palmatine, berberine, baicalin, and geniposide from HJD according to the quantity of HJD. The detailed mechanisms of the active components from HJD and ACF in sepsis treatment are unclear. Molecular docking, surface plasmon resonance (SPR), ELISA, RT-qPCR, and Western blotting were used to assay the possible mechanism in vitro. The efficacy and mechanism of ACF and HJD were assessed by pharmacodynamics and metabolomics analyses, respectively. The results revealed that palmatine, berberine, baicalin, and geniposide showed good binding capacity to MD-2; decreased the release of NO, TNF-α, IL-6, and IL-1β; inhibited the mRNA expression of iNOS, TNF-α, IL-6, IL-1β, and COX-2; and downregulated the protein expressions of MD-2, MyD88, p-p65, and iNOS induced by LPS; which indicated that they can inactivate the LPS-TLR4/MD-2-NF-κB pathway. Thus, ACF was formed, and the pharmacodynamics assay suggested that ACF can reduce inflammatory cell infiltration and organ damage in accordance with HJD. Furthermore, 39 metabolites were selected and identified and the regulatory effect of these metabolites by ACF and HJD was almost consistent, but ACF might alleviate physical damage caused by HJD through regulating metabolites, such as 3-hydroxyanthranilic acid. ACF could represent HJD as a new formulation to treat sepsis. [ABSTRACT FROM AUTHOR]

The outbreak of the COVID-19 pandemic was partially due to the challenge of identifying asymptomatic and presymptomatic carriers of the virus, and thus highlights a strong motivation for diagnostics with high sensitivity that can be rapidly deployed. On the other hand, several concerning SARS-CoV-2 variants, including Omicron, are required to be identified as soon as the samples are identified as 'positive'. Unfortunately, a traditional PCR test does not allow their specific identification. Herein, for the first time, we have developed MOPCS (Methodologies of Photonic CRISPR Sensing), which combines an optical sensing technology-surface plasmon resonance (SPR) with the 'gene scissors' clustered regularly interspaced short palindromic repeat (CRISPR) technique to achieve both high sensitivity and specificity when it comes to measurement of viral variants. MOPCS is a low-cost, CRISPR/Cas12a-system-empowered SPR gene-detecting platform that can analyze viral RNA, without the need for amplification, within 38 min from sample input to results output, and achieve a limit of detection of 15 fM. MOPCS achieves a highly sensitive analysis of SARS-CoV-2, and mutations appear in variants B.1.617.2 (Delta), B.1.1.529 (Omicron) and BA.1 (a subtype of Omicron). This platform was also used to analyze some recently collected patient samples from a local outbreak in China, identified by the Centers for Disease Control and Prevention. This innovative CRISPR-empowered SPR platform will further contribute to the fast, sensitive and accurate detection of target nucleic acid sequences with single-base mutations. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019, a newly emerging serious infectious disease, has spread worldwide. To date, effective drugs against the disease are limited. Traditional Chinese medicine was commonly used in treating COVID‐19 patients in China. Here we tried to identify herbal effective lipid compounds from the lipid library of 92 heat‐clearing and detoxication Chinese herbs. Through virtual screening, enzymatic activity and inhibition assays, and surface plasmon resonance tests, we identified lipid compounds targeting the main protease (Mpro) of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and verified their functions. Here, we found that natural lipid compounds LPC (14:0/0:0) and LPC (16:0/0:0) could target SARS‐CoV‐2 Mpro, recover cell death induced by SARS‐CoV‐2, and ameliorate acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) induced by bacterial lipopolysaccharides and virus poly (I:C) mimics in vivo and in vitro. Our results suggest that LPC (14:0/0:0) and LPC (16:0/0:0) might be potential pan remedy against ARDS. [ABSTRACT FROM AUTHOR]

Janus kinase 2 (JAK2) hyperactivation by JAK2V617F mutation leads to myeloproliferative neoplasms (MPNs) and targeting JAK2 could serve as a promising therapeutic strategy for MPNs. Here, we report that Flonoltinib Maleate (FM), a selective JAK2/FLT3 inhibitor, shows high selectivity for JAK2 over the JAK family. Surface plasmon resonance assays verified that FM had a stronger affinity for the pseudokinase domain JH2 than JH1 of JAK2 and had an inhibitory effect on JAK2 JH2V617F. The cocrystal structure confirmed that FM could stably bind to JAK2 JH2, and FM suppressed endogenous colony formation of primary erythroid progenitor cells from patients with MPNs. In several JAK2V617F-induced MPN murine models, FM could dose-dependently reduce hepatosplenomegaly and prolong survival. Similar results were observed in JAK2V617F bone marrow transplantation mice. FM exhibited strong inhibitory effects on fibrosis of the spleen and bone marrow. Long-term FM treatment showed good pharmacokinetic/pharmacodynamic characteristics with high drug exposure in tumor-bearing tissues and low toxicity. Currently, FM has been approved by the National Medical Products Administration of China (CXHL2000628), and this study will guide clinical trials for patients with MPNs. [ABSTRACT FROM AUTHOR]

Nasopharyngeal carcinoma (NPC) is consistently associated with Epstein-Barr virus (EBV) latent infection and is common in Southern China and Southeast Asia. The viral latent membrane proteins LMP1 and LMP2 are persistently expressed in NPC tissues; the cytoplasmic domain of LMP1 (LMP1 C-terminal) and LMP2A (LMP2A N-terminal) proteins is essential for maintenance of latency and can alter host cell signaling to facilitate tumor growth and progression. Thus, targeting LMP1 or LMP2 oncoprotein has been an increasing interest for diagnosis and targeted therapy of NPC. Affibody molecules, a new class of small-affinity engineered scaffold proteins, have demonstrated high potential for therapeutics, diagnostics, and biotechnological applications. More recently, radiolabelled HER2-specific affibody molecules have demonstrated to be useful in imaging of HER2 expressing tumor. In this study, we report three novel EBV LMP1 C-terminal (EBV LMP1-C) domain affibody molecules (ZLMP1-C15, ZLMP1-C114, and ZLMP1-C277) were selected by biopanning from a random-peptide displayed phage library and used for molecular imaging in tumor-bearing nude mice. Surface plasmon resonance (SPR), indirect immunofluorescence, and immunohistochemistry (IHC) clearly showed that all three selected affibody molecules have high affinity and specificity in binding to EBV LMP1 protein. Moreover, in vivo tumor imaging revealed that Dylight-755-labeled affibody molecules accumulated rapidly in tumor site after injection (1 h) and then were continuously maintained for 24 h in EBV-positive NPC xenograft mice model. In conclusion, our findings highlight the potential use of ZLMP1-C affibody molecules as tumor-specific molecular imaging agents of EBV-associated NPC. Key points • We screened three novel affibody molecules (ZLMP1-C15, ZLMP1-C114, and ZLMP1-C277) targeting EBV LMP1-C terminal domain • ZLMP1-C recognize the recombinant and native LMP1-C with high affinity and specificity • ZLMP1-C can be used for molecular imaging [ABSTRACT FROM AUTHOR]

Traditional Chinese medicines played an important role in the treatment of COVID-19 in 2020. Ephedra sinica, one of the major constituent herbs of multi-component herbal formula, has been widely used to treat COVID-19 in China. However, its active components are still unclear. The objectives of this study are to screen and evaluate active components from the traditional Chinese medicine Ephedra sinica for the treatment of COVID-19. In our study, we established an ACE2/CMC bioaffinity chromatography model, and then developed an ACE2/CMC-HPLC-IT-TOF-MS system for the active compounds screening and identification from Ephedra sinica extract. We performed molecular docking and surface plasmon resonance (SPR) assays to assess the binding characteristics (binding mode and KD value). We used CCK-8 staining to assess the toxicity of screened compounds, and also used SARS-CoV-2 pseudovirus to observe the viropexis effect of screened compounds in ACE2h cells. In this current work, one fraction was fished out, separated and identified as ephedrine (EP), pseudoephedrine (PEP), and methylephedrine (MEP). Binding assays showed that the three compounds could bind with ACE2 in a special way to some amino acid residues, similar to the way SARS-CoV-2 bound with ACE2. Additionally, the three compounds, especially EP, can inhibit the entrance of SARS-CoV-2 spike pseudovirus into ACE2h cells because they can reduce the entrance ratio of pseudovirus in the pseudovirus model. Overall, the ACE2/CMC-HPLC-IT-TOF-MS system was established and verified to be suitable for ACE2-targeted bioactive compound screening. EP, PEP, and MEP with ACE2-binding features were screened out from Ephedra sinica, and acted as blockers inhibiting SARS-CoV-2 spike pseudovirus entering ACE2h cells. [ABSTRACT FROM AUTHOR]

• A 3D free-standing photo-catalyst Ag NPs/ZnO NAs/NiF was successfully prepared. • The enhanced photo-catalytic performance for degradation of berberine was obtained. • The photo-degradation intermediates of berberine and mechanisms were proposed. • The Ag NPs/ZnO NAs/NiF photo-anode was applied in PFC with effective performance. Berberine is a widely used antibiotic in China, its photocatalytic degradation is not well understood nor its efficient treatment reported. In this study, it is most quickly and efficiently degraded (97.9% under UV and 98.9% under visible light) using a free-standing 3D composite photo-electrode, with well dispersed Ag nanoparticles (Ag NPs) over well-aligned ZnO nanorods arrays (ZnO NAs) on Ni foam (NiF), compared to ZnO NAs/NiF, ZnO powder and P25. The composite photo-electrode was prepared by first directly growing ZnO NAs on NiF hydrothermally, followed by photo-deposition of Ag NPs, without any inactive binders or non-conductive substrates. It was characterized using scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), X-ray Diffraction (XRD), ultraviolet–visible spectrophotometry (UV–Vis) and electrochemical analysis (I-t, EIS). The highest activity of Ag NPs/ZnO NAs/NiF in degrading the target pollutant, is due to the synergy of easy pollutants diffusion and fast reaction on active sites, from suppressed electron-hole recombination by Ag NPs/ZnO NAs heterojunctions, extended light absorption by surface plasmon resonance (SPR) of Ag NPs and accelerated electron transport on the conductive macro-porous NiF. The reactive oxidizing species (OH, O 2 −, h±), degradation intermediates and possible degradation pathways of berberine over Ag NPs/ZnO NAs/NiF were examined respectively. This free-standing whole piece photo-electrode with UV–visible light response, is easy to recycle and assemble, that not only degrades pollutant, but also generates electricity as photo-anode in a photo-catalytic fuel cell reactor using carbon fiber cloth as cathode. [ABSTRACT FROM AUTHOR]

The venomous species Deinagkistrodon acutus has been used as anti-inflammatory medicine in China for a long time. It has been proven to have anti-inflammatory activity, but its specific anti-inflammatory components have not yet been fully elucidated. Tumor necrosis factor receptor-1 (TNFR1), which participates in important intracellular signaling pathways, mediates apoptosis, and functions as a regulator of inflammation, is often used as the target to develop anti-inflammatory drugs. The small peptides of snake venom have the advantages of weak immunogenicity and strong activity. To obtain the specific TNFR1 binding peptides, we constructed a T7 phage library of D. acutus venom glands, and then performed biopanning against TNFR1 on the constructed library. After biopanning three times, several sequences with potential binding capacity were obtained and one 41-amino acid peptide was selected through a series of biological analyses including sequence length, solubility, and simulated affinity, named DAvp-1. After synthesis, the binding capacity of DAvp-1 and TNFR1 was verified using surface plasmon resonance technology (SPR). Conclusively, by applying phage display technology, this work depicts the successful screening of a promising peptide DAvp-1 from D. acutus venom that binds to TNFR1. Additionally, our study emphasizes the usefulness of phage display technology for studies on screening natural product components. [ABSTRACT FROM AUTHOR]

In the work, a rapid and accurate biosensor for mercury ions (Hg 2+ ) was constructed, with which aggregation of dual-modified (DGPFHR- and CALNN-) gold nanoparticles (D/C-AuNPs) could be triggered by the high specificity of peptides to Hg 2+ . The given peptide DGPFHR possesses great capability of capturing Hg 2+ , accompanied by the conformational folding. Under the circumstances, D/C-AuNPs were employed as the detection probes to accomplish the quantitative analysis of Hg 2+ . This is primarily because the specific Hg 2+ -induced folding of peptides reduces the electrostatic repulsion and steric hindrance, thus accelerating the AuNPs aggregation. The principle and application potential of this proposal was proved by evidence. And the results demonstrated that Hg 2+ ions could be selectively detected as low as 28 nM with a linear range of 100-800 nM. In consideration of superior simplicity, selectivity, accuracy and stability, the protocol was advantageous over other projects in practical measurement of various water samples., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Imported malaria has become a major risk factor for malaria prevention and control in China. How to screen malaria quickly for people entering China is an urgent problem to be solved. Protein microarrays are widely used in high-throughput screening and diagnosis. In this study, surface plasmon resonance (SPR) technique for malaria detection was established by using the specific adsorption surface treated by polyethylene glycol polymer, and the malaria specific antigen HRP2 was used as capture probe. The optimal concentration of antigen, sensitivity and specificity of detection, as well as anti-interference ability of the chip were analyzed. The SPR protein chip was applied to detect specific antibodies of malignant malaria in serum with the advantage of label-free, instant and fast. Compared with fluorescence quantitative PCR, there were no significant difference in sensitivity and specificity between the two methods. This study lays a foundation for further development of protein microarray for malaria typing identification, and it is conducive to the rapid screening of malaria for people entering.

• Immunoassays without dissolution process was used in antigenicity assessment. • Multiple assays were used for functional characterization of the HEV vaccine. • Feasibility of labelling the vaccine for the WHO CTC use was demonstrated. • No changes in quality attributes of an HEV vaccine at the end of expiry dating. Hepatitis E, which is caused by infection with hepatitis E virus (HEV), is a global health problem in both developed and developing countries. An efficacious hepatitis E vaccine was licensed (by China) in 2011 with a trade name of Hecolin®. The antigen contained in this vaccine is a truncated version of the sole capsid protein encoded by open reading frame 2, which is designated p239. In this study, the real-time and real-condition stability and accelerated stability of five lots of hepatitis E vaccine products at the end of the designated shelf life, were assessed by a well-established quality analysis platform. The protein integrity of p239 that was recovered from the vaccine lots was demonstrated using CE-SDS, LC-MS and MALDI-TOF MS. The particle characteristics of the recovered vaccine antigen were assessed by TEM and HPSEC. The immunogenicity of hepatitis E vaccines was assessed by a mouse potency assay, which is part of product release and stability testing. Several methods were employed to assess the antigenicity of vaccines with or without adjuvant dissolution. Specifically, the well-established methods of sandwich ELISA and surface plasma resonance (SPR)-based BIAcore were used with unique murine monoclonal antibodies. Most interesting, two 'dissolution-free' immunoassays were also used for in situ antigenicity assessment of the vaccines. In addition to the confirmation of vaccine stability at the end of expiry dating, i.e., after storage in recommended conditions (2–8 °C) for 36 months, the mouse potency assay and sandwich ELISA were used to assess the accelerated stability of prefilled syringes to demonstrate the feasibility of out-of-cold-chain storage. In summary, molecular and functional characterization confirmed the shelf life stability of the vaccine at the end of expiry dating and the feasibility of transporting the hepatitis E vaccine for a given period of time out of cold chains. [ABSTRACT FROM AUTHOR]

Background: Gandi capsule is a traditional Chinese herbal formula used to promote blood circulation and removing blood stasis in clinical. Our previous study has shown that it reduces proteinuria with routine treatment in diabetic nephrophy (DN), but its pharmacological action mechanism is still unknown., Methods: To facilitate the identification of components, a component database of Gandi capsule and target database of DN were established by ourselves. The components absorbed in blood circle were identified in rat plasma after oral administration of Gandi capsule by UHPLC-QQQ-MS/MS. The potential targets were screened by using Libdock tolls in Discovery studio 3.0. Then Pathway and Network analyses were used to enrich the screened targets. The possible targets were verified by using a surface plasmon resonance (SPR) test and the molecular mechanism focusing these targets for treating DN was clarified by western blot., Results: Six components in Gandi capsule were identified detected in rat plasma after oral administration by UHPLC-QQQ-MS/MS. After molecular docking analyses in KEGG and Discovery studio, four protein targets including HNF4A, HMGCR, JAK3, and SIRT1, were screened out, and proved as effective binding with baicalin, wogonoside by SPR. And the molecular mechanism was clarified that baicalin and wogonoside inhibit the effect of high glucose (HG)-induced decreased cell viability and podocin expression, and strengthen the activation p-AKT, p-PI3K, and p-AMPK., Conclusion: Baicalin and wogonoside were screened out to be the active compounds in Gandi capsule and can ameliorate HG-induced podocyte damage by influencing the AMPK and PI3K-AKT signaling pathways by binding with HNF4A, HMGCR, JAK3, and SIRT1.

Here we describe an industry-wide collaboration aimed at assessing the binding properties of a comprehensive panel of monoclonal antibodies (mAbs) against programmed cell death protein 1 (PD-1), an important checkpoint protein in cancer immunotherapy and validated therapeutic target, with well over thirty unique mAbs either in clinical development or market-approved in the United States, the European Union or China. The binding kinetics of the PD-1/mAb interactions were measured by surface plasmon resonance (SPR) using a Carterra LSA instrument and the results were compared to data collected on a Biacore 8K. The effect of chip type on the SPR-derived binding rate constants and affinities were explored and the results compared with solution affinities from Meso Scale Discovery (MSD) and Kinetic Exclusion Assay (KinExA) experiments. When using flat chip types, the LSA and 8K platforms yielded near-identical kinetic rate and affinity constants that matched solution phase values more closely than those produced on 3D-hydrogels. Of the anti-PD-1 mAbs tested, which included a portion of those known to be in clinical development or approved, the affinities spanned from single digit picomolar to nearly 425 nM, challenging the dynamic range of our methods. The LSA instrument was also used to perform epitope binning and ligand competition studies which revealed over ten unique competitive binding profiles within this group of mAbs., Competing Interests: MEB, AL, MV, SD, IW-M, LZ, JHN, IB, IC, HL, MS, TS, JB and YX are past or present employees and/or shareholders of Adimab LLC. DB and YNA are currently employed at Carterra. PR is currently an employee at Amgen and a shareholder of Amgen. These commercial affiliations do not alter our adherence to PLOS ONE policies on sharing data and materials. Adimab collaborated in the discovery of, and filed patents on, sintilimab approved for marketing in China, an analog of which (mAb21) was included in this study.

No study examined the frequency of human papillomavirus (HPV) genotypes by surface plasmon resonance (SPR) in Southwest China. This was a cross-sectional survey (The Second Affiliated Hospital of Kunming Medical University, 10/2010 to 12/2011) in 150 patients who were hospitalized or volunteered for cervical cancer (CC) screening. A HPV typing kit was used to detect 24 types of HPV by the SPR technique. The HPV-positive rate was 34.8% in women with normal cytology and 92.9% in women with CC. The frequency of HPV16 increased from 9.4% for women with normal cytology to 28.9% for cervical intraepithelial neoplasia (CIN)1, 41.4% for CIN2, 54.1% for CIN3, and 71.4% for CC (p < 0.001). The frequency of HPV18 increased from 0% for women with normal cytology to 2.6% for CIN1, 3.4% for CIN2, 5.4% for CIN3, and 21.4% for CC (p = 0.03). HPV40 was only found in one patient with CC (p = 0.04). There was no relation between HPV genotype and women's age. In Kunming (Southwest China), the frequency of HPV infection was 74.0% among women who underwent CC screening. HPV16 and HPV18 were the two most frequent genotypes. SPR could be of value for the screening of HPV infection.

Bacterial stem and root rot disease of sweet potato caused by Dickeya dadantii recently broke out in major sweet potato planting areas in China and calls for effective approaches to control the pathogen and disease. Here, we developed a simple method for green synthesis of silver nanoparticles (AgNPs) using bacterial culture supernatants. AgNPs synthesized with the cell-free culture supernatant of a bacterium Pseudomonas rhodesiae displayed the characteristic surface plasmon resonance peak at 420–430 nm and as nanocrystallites in diameters of 20–100 nm determined by transmission electron microscopy, scanning electron microscopy, and X-ray diffraction spectroscopy. Functional groups associated with proteins in the culture supernatant may reduce silver ions and stabilize AgNPs. The AgNPs showed antibacterial activities against D. dadantii growth, swimming motility, biofilm formation, and maceration of sweet potato tubers whereas the culture supernatant of P. rhodesiae did not. AgNPs (12 µg∙ml−1) and AgNO3 (50 µg∙ml−1) showed close antibacterial activities. The antibacterial activities increased with the increase of AgNP concentrations. The green-synthesized AgNPs can be used to control the soft rot disease by control of pathogen contamination of sweet potato seed tubers. [ABSTRACT FROM AUTHOR]

Background: This study was performed to evaluate the surface plasmon resonance-based (SPR) test with the W2600 System of GP Medical Technologies as a screening method for human papillomavirus (HPV) genotyping in China., Methods: Between November 2012 and December 2013, the SPR test, hybrid capture II (HC2) test, and direct DNA sequencing assay were performed on 424 patients aged 22 - 65 years who attended the outpatient clinic at the Department of Obstetrics and Gynecology of West China Second University Hospital with diagnoses of chronic cervicitis or abnormal vaginal bleeding. Cervical specimens were collected from the cervical epithelia. Cytological and histological studies were also performed., Results: A total of 424 patient specimens were screened. The positive, negative, and overall concordance between the SPR test and HC2 test was 93.48%, 89.16%, and 90.57%, respectively. The concordance between the SPR test and the direct DNA sequencing assay was 97.41%. Against the results of the direct DNA sequencing assay, the SPR test demonstrated a sensitivity of 96.86% and a specificity of 97.74%., Conclusions: The SPR test is reliable, sensitive, and specific for HPV genotyping. Compared to the hybrid-capture assay, the SPR test may work on more than one specimen at a time and is a low-cost, rapid, and easy-to-use method with the potential for automation. The SPR test may be widely employed in China and other countries for HPV genotyping.

Developing reagents with high affinity and specificity are critical to detect the environmental hormones or toxicants. Ribosome display technology has been widely used in functional protein or peptide screening and in directed evolution of protein molecules in vitro. In this study, single-chain variable fragments (scFvs) against bisphenol A (BPA) were selected from a library constructed from splenocytes of non-immunized mice. After five rounds of selection, the selected scFvs bound to BPA with high affinity. Indirect competitive enzyme-linked immunosorbent assay (ELISA) was introduced to screen the antibody affinity and specificity to BPA. The equilibrium dissociation constants (KDS) of one clone was 1.76μM as determined by surface plasmon resonance (SPR). This study indicated that ribosome display can isolate binders to small molecules from a non-immunized naive library without any in vivo steps and can generate recombinant antibodies efficiently and rapidly. In addition, this study provides a methodological framework for detection of small molecules using recombinant antibodies., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Since December 2013, at least three cases of human infections with H10N8 avian influenza virus have been reported in China, two of them being fatal. To investigate the epidemic potential of H10N8 viruses, we examined the receptor binding property of the first human isolate, A/Jiangxi-Donghu/346/2013 (JD-H10N8), and determined the structures of its haemagglutinin (HA) in complex with both avian and human receptor analogues. Our results suggest that JD-H10N8 preferentially binds the avian receptor and that residue R137-localized within the receptor-binding site of HA-plays a key role in this preferential binding. Compared with the H7N9 avian influenza viruses, JD-H10N8 did not exhibit the enhanced binding to human receptors observed with the prevalent H7N9 virus isolate Anhui-1, but resembled the receptor binding activity of the early-outbreak H7N9 isolate (Shanghai-1). We conclude that the H10N8 virus is a typical avian influenza virus.

Background: Although recent genome-wide association studies have been conducted to reveal the relation between variations in the α5 nicotinic receptor subunit and lung cancer in European and American populations, to the authors' knowledge, no definite information on the role of nicotine acetylcholine receptor subunit α5 (CHRNA5) in lung cancer risk has been obtained in a Chinese population., Methods: To test this possible association, a case-control study was conducted in 505 patients with lung cancer (cases) and a control group of 498 cancer-free individuals., Results: Participants were screened for variations in the CHRNA5 promoter region by sequencing, and 2 common polymorphisms were selected at -1640 (reference single nucleotide polymorphism identifier rs3829787 cytosine to thymine [C→T]) and at -62 (rs3841324 insertion→deletion [ins→del]) from the transcription start site of the CHRNA5 gene. Haplotype analysis revealed that the 2 least frequent haplotypes (T/ins and C/del) were statistically protective against lung cancer (P = .0002 and P = .0094, respectively). Unexpectedly, the luciferase results indicated that these 2 protective haplotype constructs had the extremely opposite promoter activity in various cells: the T/ins haplotype had the highest activity and the C/del haplotype had the lowest activity. Surface plasmon resonance demonstrated that both minor alleles (T and del) decreased DNA binding affinity to nuclear extracts, which the authors presumed was responsible for the disparity in promoter activity., Conclusions: The current results indicated that the CHRNA5 gene with under-activated or over-activated promoter activity may be protective against lung cancer. These results indicated a new associated risk pattern between CHRNA5 promoter activity and susceptibility to lung cancer that implies a complex role of the CHRNA5 gene in lung cancer., (Copyright © 2011 American Cancer Society.)