The possibility of using polarography for the diagnosis of radiation damage

The polarographic method permitted to register changes in the protein higher structure at radiation doses of the order of tenths Gy. A technique is proposed and optimum conditions found for taking measurements in mammalian serum and plasma in vitro. It is suggested that the proposed technique, having been tested on experimental animals, might be used for an indirect diagnosis of radiation affection in human beings.     

蛋白质糖基化修饰的研究方法及其应用

蛋白质糖基化是一种重要的翻译后修饰,它参与和调控生物体的许多生命活动。随着蛋白质组技术的不断发展,蛋白质糖基化研究越来越受到广泛的重视。本文介绍了蛋白质糖基化修饰的研究内容与方法,并综述了最近的研究进展。     

壳聚糖的结构修饰及其应用

壳聚糖是甲壳素的衍生物,其水溶性较差。为了改善其溶解性,拓宽其应用范围,根据其结构特点对其进行化学修饰,制得多种衍生物。该就其在羧基化、酰基化、烷基化、醚化等方面的修饰及其应用进行综述。     

Type IV Pilin Post-Translational Modifications Modulate Material Properties of Bacterial Colonies

Bacterial type 4 pili (T4P) are extracellular polymers that initiate the formation of microcolonies and biofilms. T4P continuously elongate and retract. These pilus dynamics crucially affect the local order, shape, and fluidity of microcolonies. The major pilin subunit of the T4P bears multiple post-translational modifications. By interfering with different steps of the pilin glycosylation and phosphoform modification pathways, we investigated the effect of pilin post-translational modification on the shape and dynamics of microcolonies formed by Neisseria gonorrhoeae. Deleting the phosphotransferase responsible for phosphoethanolamine modification at residue serine 68 inhibits shape relaxations of microcolonies after perturbation and causes bacteria carrying the phosphoform modification to segregate to the surface of mixed colonies. We relate these mesoscopic phenotypes to increased attractive forces generated by T4P between cells. Moreover, by deleting genes responsible for the pilin glycan structure, we show that the number of saccharides attached at residue serine 63 affects the ratio between surface tension and viscosity and cause sorting between bacteria carrying different pilin glycoforms. We conclude that different pilin post-translational modifications moderately affect the attractive forces between bacteria but have severe effects on the material properties of microcolonies.