Ueno H, Katoh T, Morita F
J Biochem. 1985 Jun;97(6):1785-93. doi: 10.1093/oxfordjournals.jbchem.a135237.
The alkali light chain of rabbit skeletal muscle myosin, A1, was cyanylated with 2-nitro-5-thiocyanobenzoic acid, and the peptide bond at Cys 177 was subsequently cleaved in the presence of 0.05 M CaCl2. Two peptide fragments, from the N-terminal to the residue 176 (CF1) and from the residue 177 to the C-terminal (CF2), were obtained. The CD spectrum and the difference UV absorption spectrum induced by CaCl2 suggested that CF1 largely retained the higher order structure of A1. The CF1 fragment, however, could neither incorporate subfragment-1 (S-1) by an exchange reaction, nor bind with the renatured 20K fragment of S-1 heavy chain. On the other hand, the C-terminal fragment of 14 residues, CF2, could bind with the 20K fragment of S-1 heavy chain. These results indicate that the binding site of the alkali light chain for the heavy chain of myosin is located within the C-terminal 14 residues.
兔骨骼肌肌球蛋白的碱性轻链A1用2-硝基-5-硫氰基苯甲酸进行氰化处理，随后在0.05 M氯化钙存在的情况下，177位半胱氨酸处的肽键被切断。得到了两个肽片段，从N端到176位残基（CF1）以及从177位残基到C端（CF2）。圆二色光谱以及氯化钙诱导的紫外吸收差光谱表明，CF1很大程度上保留了A1的高级结构。然而，CF1片段既不能通过交换反应并入亚片段-1（S-1），也不能与S-1重链的复性20K片段结合。另一方面，14个残基的C端片段CF2能够与S-1重链的20K片段结合。这些结果表明，肌球蛋白碱性轻链与重链的结合位点位于C端的14个残基内。
