Provided is a method for characterising a polypeptide or a population of polypeptides, which method comprises the steps of:
(a) Optionally reducing disulphide linkages in the polypeptides, if they are present, and capping free thiols in the polypeptides, if they are present;
(b) contacting a sample comprising one or more polypeptides with a sequence specific cleavage reagent which cleaves one or more polypeptides on the C-terminal side of a lysine residue to produce peptide fragments;
(c) optionally deactivating the cleavage reagent;
(d) contacting the sample with a lysine reactive agent to cap ε-amino groups;
(e) removing those peptides having capped ε-amino groups; and
(f) recovering the C-terminal peptides
提供了一种表征
多肽或
多肽种群的方法,该方法包括以下步骤:
(a) 可选地还原
多肽中的二
硫键(如果存在),并封闭
多肽中的游离巯基(如果存在);
(b) 用序列特异性切割试剂接触含有一个或多个
多肽的样品,该试剂在赖
氨酸残基的C-末端侧切割一个或多个
多肽以产生肽片段;
(c) 可选地去活化切割试剂;
(d) 用赖
氨酸反应试剂接触样品以封闭ε-
氨基团;
(e) 去除具有已封闭ε-
氨基团的肽片段;
(f) 回收C-末端肽片段。