Pharmacokinetics, Safety, and Tolerability of Single-Dose Orally Administered Venglustat in Healthy Chinese Volunteers.

BACKGROUND AND OBJECTIVE: Deficiencies of enzymes acting downstream of glucosylceramide synthase (GCS) can cause severe substrate accumulation. Venglustat is a small-molecule, brain-penetrant GCS inhibitor under investigation for multiple diseases involving pathogenic glycosphingolipid accumulation. Here, we evaluate the pharmacokinetics, safety, and tolerability of venglustat in healthy Chinese volunteers. METHODS: Study PKM16116 was a phase I, single-center, non-randomized, open-label study to investigate the pharmacokinetics, safety, and tolerability of a single 15 mg dose of orally administered venglustat in healthy Chinese volunteers aged 18 to 45 years. RESULTS: A total of 14 volunteers (7 male; 7 female) with a body mass index from 20.9 kg/m2 to 27.1 kg/m2 were enrolled. The median time to reach the venglustat maximum plasma concentration was 2.50 h post-dose. The mean terminal half-life of venglustat was 30.6 ± 7.40 h. The mean systemic exposures across all participants were 60.3 ± 17.3 ng/mL for the maximum plasma concentration, and 2280 ± 697 ng·h/mL for the area under the plasma concentration-time curve extrapolated to infinity. There were no relevant differences in venglustat pharmacokinetics between male and female volunteers. A post hoc cross-study comparison analysis showed comparable venglustat pharmacokinetics in Chinese and non-Chinese volunteers. Venglustat was safe and well tolerated in the current study (a total of five Grade 1 treatment-emergent adverse events were reported in three volunteers). CONCLUSION: Venglustat showed a favorable pharmacokinetic, safety, and tolerability profile in healthy Chinese volunteers following a single oral 15 mg dose. CLINICAL TRIAL REGISTRY NO: CTR20201012 ( http://www.chinadrugtrials.org.cn ) registered on 24 February 2021 and ChiCTR2200066559 ( http://www.chictr.org.cn ) retrospectively registered on 9 December 2022.

Ultrasound Improved the Non-Covalent Interaction of ß-Lactoglobulin with Luteolin: Regulating Human Intestinal Microbiota and Conformational Epitopes Reduced Allergy Risks.

The present study aims to investigate the effects of ultrasound on the non-covalent interaction of ß-lactoglobulin (ß-LG) and luteolin (LUT) and to investigate the relationship between allergenicity and human intestinal microbiota. After treatment, the conformational structures of ß-LG were changed, which reflected by the decrease in α-helix content, intrinsic fluorescence intensity and surface hydrophobicity, whereas the ß-sheet content increased. Molecular docking studies revealed the non-covalent interaction of ß-LG and LUT by hydrogen bond, van der Walls bond and hydrophobic bond. ß-LG-LUT complex treated by ultrasound has a lower IgG/IgE binding ability and inhibits the allergic reaction of KU812 cells, depending on the changes in the conformational epitopes of ß-LG. Meanwhile, the ß-LG-LUT complex affected the composition of human intestinal microbiota, such as the relative abundance of Bifidobacterium and Prevotella. Therefore, ultrasound improved the non-covalent interaction of ß-LG with LUT, and the reduction in allergenicity of ß-LG depends on conformational epitopes and human intestinal microbiota changes.

Prediction of protein folding rates from simplified secondary structure alphabet.

Protein folding is a very complicated and highly cooperative dynamic process. However, the folding kinetics is likely to depend more on a few key structural features. Here we find that secondary structures can determine folding rates of only large, multi-state folding proteins and fails to predict those for small, two-state proteins. The importance of secondary structures for protein folding is ordered as: extended ß strand > α helix > bend > turn > undefined secondary structure>310 helix > isolated ß strand > π helix. Only the first three secondary structures, extended ß strand, α helix and bend, can achieve a good correlation with folding rates. This suggests that the rate-limiting step of protein folding would depend upon the formation of regular secondary structures and the buckling of chain. The reduced secondary structure alphabet provides a simplified description for the machine learning applications in protein design.

Reduced alphabet for protein folding prediction.

What are the key building blocks that would have been needed to construct complex protein folds? This is an important issue for understanding protein folding mechanism and guiding de novo protein design. Twenty naturally occurring amino acids and eight secondary structures consist of a 28-letter alphabet to determine folding kinetics and mechanism. Here we predict folding kinetic rates of proteins from many reduced alphabets. We find that a reduced alphabet of 10 letters achieves good correlation with folding rates, close to the one achieved by full 28-letter alphabet. Many other reduced alphabets are not significantly correlated to folding rates. The finding suggests that not all amino acids and secondary structures are equally important for protein folding. The foldable sequence of a protein could be designed using at least 10 folding units, which can either promote or inhibit protein folding. Reducing alphabet cardinality without losing key folding kinetic information opens the door to potentially faster machine learning and data mining applications in protein structure prediction, sequence alignment and protein design.

Catalytic and inhibitory kinetic behavior of horseradish peroxidase on the electrode surface.

Enzymatic biosensors are often used to detect trace levels of some specific substance. An alternative methodology is applied for enzymatic assays, in which the electrocatalytic kinetic behavior of enzymes is monitored by measuring the faradaic current for a variety of substrate and inhibitor concentrations. Here we examine a steady-state and pre-steady-state reduction of H(2)O(2) on the horseradish peroxidase electrode. The results indicate the substrate-concentration dependence of the steady-state current strictly obeys Michaelis-Menten kinetics rules; in other cases there is ambiguity, whereby he inhibitor-concentration dependence of the steady-state current has a discontinuity under moderate concentration conditions. For pre-steady-state phases, both catalysis and inhibition show an abrupt change of the output current. These anomalous phenomena are universal and there might be an underlying biochemical or electrochemical rationale.