Sugar Auxiliary Group Assisted Diversity-Oriented Enzymatic Modular Synthesis of 0-Series Ganglioside Glycans.

Owing to the inaccessibility of β1-4-N-acetylgalactosaminyltransferase for direct glycan chain elongation, the enzymatic synthesis of 0-series gangliosides with extended backbones has not been explored. In this study, sialic acid was enzymatically introduced as an auxiliary group to overcome the limitation of substrate specificity of Campylobacter jejuni β1-4-N-acetylgalactosaminyltransferase (CjCgtA) to achieve the synthesis of desired extended 0-series ganglioside core structures, and the sialic acid auxiliary group could be removed by sialidase at appropriate stages. A bacterial α2-6-sialyltransferase from Photobacterium damselae (Pd2,6ST) exhibited unexpected acceptor substrate specificity for 0-series ganglioside core structures, providing ready access to complex gangliosides bearing the sialyl N-acetylgalactosamine unit.

Physical activity affects dysthyreosis by thyroid hormones sensitivity: a population-based study.

Objective: Physical activity (PA) plays an important role in human health. However, the relationship between the PA and dysthyreosis was not clear. This study aimed to explore this question.

Recent advances in enzymatic and chemoenzymatic synthesis of N- and O-glycans.

Glycosylation is one of the most common post-translational modifications of proteins, which plays essential roles in regulating the biological functions of proteins. Efficient and versatile methods for the synthesis of homogeneous and well-defined N- and O-glycans remain an urgent need for biological studies and biomedical applications. Despite their structural complexity, tremendous progress has been made in the synthesis of N- and O-glycans in recent years.

New analogues of brefeldin A from sediment-derived fungus Penicillium sp. DT-F29.

Four new analogues of brefeldin A named 7, 7-dimethoxybrefeldin C (3), 6β-hydroxybrefeldin C (4), 4-epi-15-epi-brefeldin A (5), 4-epi-8α-hydroxy-15-epi-brefeldin C (6), together with four known analogues (1, 7-9) were isolated from a fermentation of the sediment-derived fungus Penicillium sp. DT-F29. The structures of these compounds were elucidated on the basis of extensive spectroscopic and chemical methods.

[Frequency and linkage disequilibrium of specific HLA-DR and HLA-DQ genes in Chinese Han population].

This study was aimed to investigate the distribution feature of HLA-DR/DQ gene linkage disequilibrium in Chinese Han population and to improve the accuracy of HLA matching results. Genotyping of HLA-DR and HLA-DQ gene locus was performed using PCR-SSP typing in Chinese Han population receiving kidney transplantation. The results showed that there were 29 new linkage combinations in 1799 patients, in which DR13-DQ5, DR11-DQ8 and DR8-DQ8 were discovered for 11, 8 and 7 times respectively while DR9-DQ8, DR12-DQ6 and DR14-DQ4 were both discovered for 6 times.