The molecular conformation of amyloid fibril revealed by pressure axis

用高压傅里叶变换红外光谱研究了压力对胰岛素淀粉样原纤维二级结构的影响。早期的淀粉样原纤维来自胰岛素的中间状态，在高达550 Mpa的高压下被融化。通过高压一维和二维核磁共振波谱研究了高压下胰岛素的详细结构。高压核磁共振显示，残基的酰胺质子化学位移变化很大，主要在B链的N-末端和C-末端以及A-链的Helix1。高压下B链N-端和C-端链的结构变化是压力诱导胰岛素分子缔合和聚集的关键因素

The pressure-induced changes in the secondary structure of insulin amyloid fibril up to 1100MPa were studied by means of the high pressure Fourier transform infrared spectroscopy. The early amyloid fibril to come from intermediate state of insulin was melted by high compression up to 550MPa. But the aged amyloid fibril does not change to be rigid structure by very high compression up to 1GPa.The detail structure of insulin under high pressure was studied by high pressure one- and two-dimensional NMR spectroscopy. High pressure NMR showed large changes in amide proton chemical shift for the residues mainly in the N- and C-terminal strands of B chain and helix1 of A-chain. The structural changes in the N- and C-terminal strands of B-chain under high pressure is a key factor for the pressure induced molecular association and aggregation of insulin