Wei J, Xie L, Lin Y Z, Tsou C L
National Laboratory of Biomacromolecules, Institute of Biophysics, Academia Sinica, Beijing, China.
Biochim Biophys Acta. 1992 Mar 27;1120(1):69-74. doi: 10.1016/0167-4838(92)90425-d.
From the amide I bands of their deconvolved FTIR spectra, the S-thiomethyl derivatives of the insulin A, B, despentapeptide(26-30) B and desoctapeptide(23-30) B chains all contain significant amounts of ordered secondary structure. The intact B chain is considerably more ordered than either the A or the truncated B chains. Comparison of the spectra of the separated and mixed intact chains of insulin suggests further folding upon mixing of the chains leading to significant increases in ordered secondary structures, presumably because of stabilization by interaction of the chains. The interactions of the A chain with the DPI B chain appear to be weaker as compared to that with the intact B chain. The above results suggest that only the intact A and B chains contain sufficient structural information to recognize each other and interact to form a native-like structure which make the correct formation of the disulfide linkages possible.
从它们解卷积后的傅里叶变换红外光谱的酰胺I带来看，胰岛素A链、B链、B链去五肽（26 - 30）和B链去八肽（23 - 30）的S-硫代甲基衍生物均含有大量有序二级结构。完整的B链比A链或截短的B链的有序程度要高得多。对分离的和混合的胰岛素完整链的光谱进行比较表明，链混合时会进一步折叠，导致有序二级结构显著增加，推测这是由于链间相互作用的稳定作用。与完整B链相比，A链与DPI B链的相互作用似乎较弱。上述结果表明，只有完整的A链和B链包含足够的结构信息以相互识别并相互作用形成类似天然的结构，从而使二硫键的正确形成成为可能。
