Dynamics of protein structure alteration at single molecular level

(1)为了在单分子水平上对蛋白质结构变化进行FRET分析，我们尝试了一种新的四碱基密码子法荧光标记牛胰蛋白酶抑制剂（BFTI）。（2）研究了中性pH条件下带负电荷的磷脂酰丝氨酸（PS）和中性磷脂酰胆碱（PC）对野生型和突变型牛胰蛋白酶抑制剂（BPTI）结构的影响。PC的存在下没有任何影响的蛋白质结构，而PS诱导的非天然结构在三个突变BPTI蛋白。然而，带负电荷的磷脂对野生型BPTI没有任何影响。研究结果表明，（i）消除一些二硫键，导致蛋白质结构发生巨大变化，（ii）这种生物化学相互作用是表面驱动的，静电相互作用可能起着重要作用。 ...更多信息 在影响蛋白质结构的上述变化中起重要作用。(3)长期接受血液透析的患者经常患有透析相关的淀粉样变性（amyloidosis，AMY）。肾衰竭是一种与肾衰竭透析治疗引起的单体β2-微球蛋白（β2-m）持续增加相关的病理学。与所有其他淀粉样蛋白一样，该蛋白形成淀粉样纤维的机制尚不清楚，当发现β2-m的淀粉样蛋白原性时，淀粉样蛋白沉积的分子基础存在很大的不确定性。在这项研究中，我们调查了接受血液透析治疗的患者血清中变异β2-m的形成。变体β2-m来源于β2-M的限制性切割。并对变异体β2-m形成的可能因素进行了估计。兹提出以下结论。变体β2-m的形成，即β2-m的限制性切割，可能由血清蛋白酶的蛋白水解切割引起。然而，尚不清楚变体β2-m是否可以触发淀粉样蛋白的形成。在来自患者的血清中蛋白质聚集形成增强。少

(1) In order to perform analysis of protein structural alteration at single molecular level using FRET method We attempted fluorescence labeling of bavine pancreatic tripsin inhibitor (BFTI) using a new technique of four base codon method. Fluorescent proteins were obtained but not enough yield for studies at molecular level(2) The effects of negatively charged phosphatidylserine (PS) and neutral phosphatidylcholine (PC) on the structure of wild-type and mutant bovine pancreatic trypsin inhibitor (BPTI) at neutral pH were investigated. The presence of PC did not have any effect on the protein structure whilst PS induced a non-native structure in three mutant BPTI proteins. However, the negatively charged phospholipid did not have any effect on wild-type BPTI. The findings revealed that (i) elimination of some disulphide bonds, results in dramatic change in protein structure, and, (ii) that this biochemical interaction is surface-driven and that electrostatic interactions may play a ver … More y strong role in influencing the fore-stated changes in protein structure.(3) Patients on long term hemodyalysis frequently suffer from dialysis-related amyloidosis (DRA). DRA is a pathology associated with a persistent increase of monomeric β2- microglobulin (β2-m) caused by dialysis treatment of renal failure. The mechanism of formation of amyloid fibrils for this protein, as for all the other amyloidogenic proteins, is not clear, and there was great uncertainty about the molecular bases of amyloid deposition when the amyloidogenicity of β2-m was discovered. In this study, we investigated formation of variant β2-m in serum of a patient who receives treatment of hemodialysis. Variant β2-m is derived from restricted cleavage of β2-M. The possible factor involved in formation of variant β2-m was also estimated. The following conclusions are proposed. Formation of variant β2-m, namely restricted cleavage of β2-m, might be caused by proteolytic cleavage by a serum protease(s). However, it is not clear whether the variant β2-m can trigger formation of amyloid. Protein aggregation formation is enhanced in serum from a patient. Less