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UFMylation involves the covalent modification of substrate proteins with UFM1 (Ubiquitin‐fold modifier 1) and is important for maintaining ER homeostasis. Stalled translation triggers the UFMylation of ER‐bound ribosomes and activates C53‐mediated autophagy to clear toxic polypeptides. C53 contains noncanonical shuffled ATG8‐interacting motifs (sAIMs) that are essential for ATG8 interaction and autophagy initiation. However, the mechanistic basis of sAIM‐mediated ATG8 interaction remains unknown. Here, we show that C53 and sAIMs are conserved across eukaryotes but secondarily lost in fungi and various algal lineages. Biochemical assays showed that the unicellular alga Chlamydomonas reinhardtii has a functional UFMylation pathway, refuting the assumption that UFMylation is linked to multicellularity. Comparative structural analyses revealed that both UFM1 and ATG8 bind sAIMs in C53, but in a distinct way. Conversion of sAIMs into canonical AIMs impaired binding of C53 to UFM1, while strengthening ATG8 binding. Increased ATG8 binding led to the autoactivation of the C53 pathway and sensitization of Arabidopsis thaliana to ER stress. Altogether, our findings reveal an ancestral role of sAIMs in UFMylation‐dependent fine‐tuning of C53‐mediated autophagy activation. Synopsis: Phylogenomic profiling has shown that UFMylation coevolves with the shuffled ATG8‐interacting motifs (sAIMs) in the ER‐phagy receptor C53. Further mechanistic analyses demonstrated that sAIMs regulate C53‐mediated autophagy by competitively binding UFM1 and ATG8.UFMylation and C53 autophagy pathways are conserved in eukaryotes, but secondarily lost in fungi and various parasitic and algal species.UFMylation is crucial for ER stress tolerance in the unicellular alga Chlamydomonas reinhardtii.Both UFM1 and ATG8 bind the shuffled AIM sequences within the intrinsically disordered domain of C53, yet their binding modes are different.Competitive binding of either UFM1 or ATG8 to C53 shuffled AIM sequences regulates C53‐mediated autophagy and ER stress tolerance. [ABSTRACT FROM AUTHOR]

Two dung beetle subspecies of Canthon rutilans Castelnau (Coleoptera: Scarabaeidae, Scarabaeinae), C. rutilans rutilans and C. rutilans cyanescens, inhabit different environmental temperature conditions in southern Brazil. We developed a laboratory breeding experiment with 60 pairs of individuals of the two subspecies at five temperature conditions (from 15 to 35 °C) to compare the influence of temperature on the behaviour of adults and the development of larvae. The behavioural patterns of the adults in both subspecies differ according to temperature. The size of food balls was smaller and lighter in C. rutilans cyanescens. Although temperature did not influence the feeding behaviour (measured as the number of food balls made), reproductive behaviour (measured as the number of brood balls made by pair) was significantly lower at 15 °C for both subspecies. Besides that, brood balls from C. rutilans rutilans were bigger and heavier at lower temperatures. The number of offspring and the time of emergence depend on temperature too. However, the weight of the offspring and the longevity of adults depend on the subspecies and temperature treatment. These results demonstrate that the subspecies have different thermal adaptations: C. rutilans rutilans has reproductive behaviour adapted to living under colder and broader conditions than C. rutilans cyanescens. [ABSTRACT FROM AUTHOR]

In this work, a methodology for the evaluation of enantioselective binding of imazalil (IMA) enantiomers to human serum albumin (HSA) that does not require the separation of free and bound to HSA fractions is developed. This methodology comprises the incubation of IMA-HSA designed mixtures for 30 min directly in the capillary electrophoresis system and the subsequent direct injection and chiral separation of IMA employing highly sulfated β-cyclodextrin as chiral selector and the complete filling technique. Two mathematical approaches were used to estimate apparent affinity constants ( K1), protein binding and enantioselectivity ( ES) for both enantiomers of IMA. Moderate enantioselective binding of IMA enantiomers to HSA ( ES = 2.0) was shown by the 1:1 stoichiometry and log K1 values of 3.4 ± 0.4 and 3.1 ± 0.3 for the first and second eluted enantiomers, respectively. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT The estimation of apparent binding constants and limit mobilities of the complexes of the enantiomers that characterize the interaction of enantiomers with chiral selectors, in this case highly sulfated β-cyclodextrin, was approached using a simple and economic electrophoretic modality, the complete filling technique (CFT) in counter-current mode. The enantiomers of eight psychoactive drugs, four antihistamines (dimethindene, promethazine, orphenadrine and terfenadine) and four antidepressants (bupropion, fluoxetine, nomifensine and viloxazine) were separated for the first time for this cyclodextrin (CD). Estimations of thermodynamic and electrophoretic enantioselectivies were also performed. Results indicate that, in general, thermodynamic enantioselectivity is the main component explaining the high resolution found, but also one case suggests that electrophoretic enantioselectivity itself is enough to obtain a satisfactory resolution. CFT results advantageous compared with conventional capillary electrophoresis (CE) and partial filling technique (PFT) for the study of the interaction between drugs and chiral selectors. It combines the use of a simple fitting model (as in CE), when the enantiomers do not exit the chiral selector plug during the separation (i.e. mobility of electroosmotic flow larger than mobility of CD), and drastic reduction of the consumption (and cost; ~99.7%) of the CD reagent (as in PFT) compared with the conventional CE. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT In this work, an electrokinetic chromatography-counter current procedure for the separation of fluoxetine enantiomers using highly sulfated β-cyclodextrin was optimized and applied to the determination of the enantiomers in three pharmaceutical formulations according to the matrix features. Quality criteria were applied to facilitate its transferability to testing laboratories. Fluoxetine was used therapeutically as the racemate, although a stereospecificity associated with its interactions with the neuronal serotonin-uptake carrier was demonstrated. In this context, the development of enantioselective methods for the chiral analysis of pharmaceuticals allowing stereoisomer ratio estimations has increasing interest in pharmaceutical industry. The proposed method allows the quantification of both enantiomers in less than 2 min with high resolution ( Rs = 2.4). Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT This report is the first evidence of enantioselective binding of nomifensine to human serum albumin (HSA) and plasma proteins. The overall process with HSA included: (i) consistent experimental design along two independent sessions; (ii) incubation of nomifensine-HSA designed mixtures; (iii) ultrafiltration for separating the unbound enantiomers fraction; (iv) electrokinetic chromatography (EKC) using heptakis-2,3,6-tri- O-methyl- β-cyclodextrin as chiral selector to provide experimental data for enantiomers (first, E1, and second, E2, eluted ones); and (v) a recent direct equation allowing univariate tests and robust statistics to provide consistent parameters and uncertainty. A significant enantioselectivity to HSA (2.7 ± 0.1) was encountered, related to a 1:1 stoichiometry and log affinity constants of 3.24 ± 0.10 and 3.67 ± 0.08 for E1 and E2, respectively. The protein binding ( PB) estimated at physiological concentration levels was 40 ± 5 and 63 ± 4% for E1 and E2, respectively. The use of synthetic human sera allowed in vitro estimation of the total plasma PB for the racemate (61 ± 5%; coincident with in vivo values), and its enantiomers (58 ± 7 and 64 ± 4% for E1 and E2, respectively). Comparison allowed the relative importance of HSA respect to other plasma proteins for binding nomifensine to be established. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to determine sex differences in facial, prosodic, and social context emotional recognition in schizophrenia (SCH). Thirty-eight patients (SCH, 20 females) and 38 healthy controls (CON, 20 females) participated in the study. Clinical scales (BPRS and PANSS) and an Affective States Scale were applied, as well as tasks to evaluate facial, prosodic, and within a social context emotional recognition. SCH showed lower accuracy and longer response times than CON, but no significant sex differences were observed in either facial or prosody recognition. In social context emotions, however, females showed higher empathy than males with respect to happiness in both groups. SCH reported being more identified with sad films than CON and females more with fear than males. The results of this study confirm the deficits of emotional recognition in male and female patients with schizophrenia compared to healthy subjects. Sex differences were detected in relation to social context emotions and facial and prosodic recognition depending on age. [ABSTRACT FROM AUTHOR]

Stereoselectivity in protein binding can have a significant effect on the pharmacokinetic and pharmacodynamic properties of chiral drugs. The investigation of enantioselectivity of drugs in their binding with human plasma proteins and the identification of the molecular mechanisms involved in the stereodiscrimination by the proteins represent a great challenge for clinical pharmacology. In this review, the separation techniques used for enantioselective protein binding experiments are described and compared. An overview of studies on enantiomer--protein interactions, enantiomer--enantiomer interactions as well as chiral drug--drug interactions, including allosteric effects, is presented. The contribution of individual plasma proteins to the overall enantioselective binding and the animal species variability in drug--plasma protein binding stereoselectivity are reviewed. [ABSTRACT FROM AUTHOR]

The determination of highly hydrophobic basic compounds by means of conventional reversed-phase liquid chromatographic methods has several drawbacks. Owing to the characteristics of micellar liquid chromatography (MLC) and capillary electrophoresis (CE), these techniques could be advantageous alternatives to reversed-phase chromatographic methods for the determination of these kinds of compounds. The objective of this study was to develop and compare MLC and CE methods for the determination of antipsychotic basic drugs (amitryptiline, haloperidol, perphenazine and thioridazine) in pharmaceutical preparations. The chromatographic determination of the analytes was performed on a Kromasil C18 analytical column; the mobile phase was 0.04 m cetyltrimethylammonium bromide (CTAB), at pH 3, containing 5% 1-butanol, at a flow rate of 1 mL/min. The CE separation was performed in a fused-silica capillary with a 50 m m tris-(hydroxymethyl)-aminomethane buffer, pH 7, at an applied voltage of 20 kV, using barbital as internal stardard. The proposed methods are suitable for a reliable quantitation of these compounds in the commercial tablets and drops in terms of accuracy and precision and require a very simple pre-treatment of the samples. By comparing the performance characteristics and experimental details of the MLC and CE methods we conclude that CE seems to be slightly better than MLC in the determination of highly hydrophobic compounds in pharmaceuticals in terms of resolution and economy, taking into account that the limits of detection are not a handicap in pharmaceutical samples. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Quantitative structure-retention relationships, QSRRs, represent a powerful tool in chromatography. The objectives of QSRR studies are to predict the chromatographic retention behaviour of solutes based on their structural properties, to elucidate retention mechanisms, to optimize the separation of complex mixtures or to prepare experimental designs. In this paper, using the retention factors of 151 structurally unrelated solutes that cover a wide range of hydrophobicity, molecular size, hydrogen bonding properties and ionization degrees obtained in biopartitioning micellar chromatography (BMC) at different Brij35 micellar concentrations, several multivariate QSRR models are tested. It is demonstrated that the chromatographic retention of any molecule in BMC, independently of its family, can be adequately described by its hydrophobicity (expressed as log P) and its anionic and cationic total molar charge (expressed as αA and αB). Copyright © 2004 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The reuptake blockade of biogenic amines by antidepressants is related not only to their therapeutics effects, but also to their side effects and potential drug-drug interactions. As an alternative to classical quantitative structure-activity relationships studies, in this work we propose different quantitative retention-activity relationships (QRAR) models that are able to describe the monoamine reuptake inhibition by antidepressants. The retention of compounds is measured using a biopartitioning micellar chromatography (BMC) system that can simulate the same hydrophobic, electronic and steric molecular interactions as those that condition drug activity. Since all the compounds considered in this work are structurally related because all of them share the same molecular features as the corresponding basic pharmacophore, the results obtained show that there is a retention range in which antidepressants present the highest monoamine reuptake inhibitor potency. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Dermal absorption of chemicals is an area of increasing interest to the pharmaceutical and cosmetic industries, as well as in dermal exposure and risk assessment processes. In this paper the capability of biopartitioning micellar chromatography (BMC) as an in vitro technique to describe compound percutaneous absorption is evaluated. A multivariate study (principal component analysis, partial least squares) is performed in order to evaluate the importance of some physicochemical variables on the skin permeability constant values. From these results, a quantitative retention–activity relationship model for predicting the skin permeability constants that uses the BMC retention data and melting point as descriptor variables was obtained from a heterogeneous set of 43 compounds. The main advantage of the proposed methodology is that it allows the obtention of permeability constants of ionic compound and it can be very useful to predict the effect of pH of vehicle on the skin permeability of xenobiotics. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]