On the specific cleavage of cysteine containing peptides and proteins.
On the specific cleavage of cysteine containing peptides and proteins.
复制标题
关于含有半胱氨酸的肽和蛋白质的特异性切割。
DOI：
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发表时间：
1977
影响因子：
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通讯作者：
G. Rossmeissl
中科院分区：
文献类型：
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作者：
C. Ebert;G. Ebert;G. Rossmeissl
将半胱氨酸添加到聚脱氢丙氨酸以及脱氢丙氨酸(DHA)和甲基半胱氨酸、丙氨酸、亮氨酸或γ-甲基-L-谷氨酸的共聚物的双键上伴随着溶解度增加和分子量降低。该结果是由于硫原子对前面的 C=O 基团的亲核攻击以及随后 OH 离子的亲核攻击导致肽键断裂而形成噻唑烷，从而导致肽键断裂。这种机制在碱性介质中占主导地位；在酸中，另一种机制受到青睐；羰基氧攻击半胱氨酸残基的羰基C原子，形成第二个环系统。添加一个水分子就会产生两个肽片段，其中之一是末端半胱氨酸残基。在γ-L-谷氨酰-脱氢丙氨酰-甘氨酸的情况下，通过添加半胱氨酸可以证实这两种机制。此外，可以证明 SH-谷胱甘肽根据提到的两种机制在高温下分解。这种SH诱导的肽键裂解可用于在相对温和的条件下选择性地裂解含半胱氨酸的多肽和蛋白质。
Addition of cysteine to the double bonds of polydehydroalanine and copolymers of dehydroalanine (DHA) and methylcysteine, alanine, leucine or gamma- methyl-L-glutamate is accompanied by increased solubility and decreased molecular weight. This result is due to a peptide bond cleavage caused by formation of a thiazolidine as a consequence of nucleophilic attack by the sulfur atom on the preceding C=O group and subsequent splitting of the peptide bond by nucleophilic attack of an OH ion. This mechanism is predominant in alkaline media; in acid another mechanism is favoured; carbonyl-oxygen attacks the carbonyl-C-atom of the cysteine residue, forming a second ring system. Addition of one water molecule then yields two peptide fragments, one of them a terminal cysteine residue. Both mechanisms could be confirmed in the case of gamma-L-glutamyl-dehydroalanyl-glycine by adding cysteine. Furthermore, it could be shown that SH-glutathione is decomposed at alevated temperatures according to the two mechanisms mentioned. This SH-induced peptide bond cleavage can be used for selective peptide chain splitting of cysteine-containing polypeptides and proteins under relatively mild conditions.