Hulmes J D, Pan Y C
Department of Protein Biochemistry, Hoffmann-La Roche Inc., Nutley, New Jersey 07110.
Anal Biochem. 1991 Sep 2;197(2):368-76. doi: 10.1016/0003-2697(91)90406-j.
Cleavage of small polypeptides (less than 30 amino acid residues) by trifluoroacetic acid (TFA) under a variety of reaction conditions including time, temperature, TFA phase, and sample supports has been examined by N-terminal sequencing. Treatment with gas-phase TFA at room temperature will cleave polypeptide chains preferentially at the N-terminal side of serine and threonine residues. When liquid-phase TFA is used, additional cleavage at the C-terminal side of aspartic acid was detected. These procedures are applicable for directly treating samples immobilized on sequencer supports (glass fiber filters or polyvinylidene difluoride membranes) to verify the presence of a polypeptide with a blocked N-terminus as well as to obtain internal sequence data at subnanomole levels.
通过N端测序研究了在包括时间、温度、三氟乙酸（TFA）相和样品支持物等多种反应条件下，三氟乙酸（TFA）对小多肽（少于30个氨基酸残基）的切割情况。在室温下用气相TFA处理会优先在丝氨酸和苏氨酸残基的N端侧切割多肽链。当使用液相TFA时，检测到在天冬氨酸的C端侧有额外切割。这些方法适用于直接处理固定在测序仪支持物（玻璃纤维滤膜或聚偏二氟乙烯膜）上的样品，以验证具有封闭N端的多肽的存在，以及获得亚纳摩尔水平的内部序列数据。
