MASS MAPPING TO SHOW DISULFIDE BOND CONNECTIVY IN PROTEINS W/ ADJACENT CYSTEINES

传统的二硫键作图方法依赖于 在所有半胱氨酸之间裂解肽骨架的蛋白酶 残留物。因为蛋白酶不能在相邻的半胱氨酸之间裂解， 含有这种结构特征的蛋白质对 传统的方法。我们已经证明了我们的氰化 方法可以裂解Long R3中邻近的半胱氨酸残基 胰岛素样生长因子(LR3IGF)是一种83个残基的蛋白质，含有 六个半胱氨酸以三个二硫键的形式存在。三、分析了 LC-MS法研究LR3IGF两种单还原异构体的切割产物 利用电喷雾电离验证了Cys60和Cys60之间的切割 已经达到了Cys61。这项研究的结果也证明了 LR3IGF-1的二硫键连接性与In同源 胰岛素样生长因子(IGF-1)。

Conventional approaches to disulfide bond mapping rely on proteases to cleave the peptide backbone between all cysteine residues. Because proteases cannot cleave between adjacent cysteines, proteins containing this structural feature are refractory to the conventional approach. We have demonstrated that our cyanylation methodology can cleave the adjacent cysteine residues in long R3 insulin-like growth factor (LR3IGF), an 83-residue protein containing six cysteines in the form of three disulfide bonds. Analysis of the cleavage products of two singly reduced isoforms of LR3IGF by LC-MS using electrospray ionization verified that cleavage between Cys60 and Cys61 had been achieved. The results of this study also proved that the disulfide connectivity in LR3IGF-1 is homologous to that in insulin-like growth factor (IGF-1).