Sarkar B, Dixon H B, Webster D
Biochem J. 1978 Sep 1;173(3):895-97. doi: 10.1042/bj1730895.
The peptide Asp-Ala-His-NH-Me was subjected to removal of its N-terminal residue by transamination and scission. Despite the high affinity of the peptide for Cu2+ ions, they catalysed its transamination smoothly. Two main transamination products were found, a complication previously observed with another peptide with an N-terminal aspartic residue, but their scission gave a single product, Ala-His-NH-Me. This was subjected to a further cycle of transamination and scission, and gave a single product after each step. For scission of transaminated peptides it proved unnecessary to remove them from transamination reagents provided that transamination was stopped with EDTA before adding the scission reagent.
肽Asp-Ala-His-NH-Me通过转氨作用和断裂反应进行N端残基的去除。尽管该肽对Cu2+离子具有高亲和力，但Cu2+离子仍能顺利催化其转氨反应。发现了两种主要的转氨产物，这是之前在另一种具有N端天冬氨酸残基的肽中观察到的复杂情况，但其断裂反应产生了单一产物Ala-His-NH-Me。对该产物进行了进一步的转氨和断裂循环，并且每一步反应后都得到单一产物。对于转氨肽的断裂反应，事实证明，只要在添加断裂试剂之前用乙二胺四乙酸（EDTA）终止转氨反应，就无需将转氨肽从转氨试剂中分离出来。
