Hass G M, Hermodson M A
Biochemistry. 1981 Apr 14;20(8):2256-60. doi: 10.1021/bi00511a029.
The amino acid sequence of a 37 residue carboxypeptidase inhibitor from tomato fruit has been determined. The amino terminus was shown to be 2-oxopyrrolidine-5-carboxylic acid by digestion of reduced and S-carboxymethylated inhibitor with pyroglutamate aminopeptidase. The remainder of the sequence was assigned by analysis of peptides which had been generated by specific cleavage at the Asp4-Pro5 bond under acid conditions and by treatment with trypsin. The amino acid sequence of this inhibitor is identical with that of an analogous inhibitor from potatoes in 26 positions, and two of the replacements are highly conservative. The identification of the nonconservative replacements has been used to better define regions of the inhibitor which are not believed to contribute significantly to the free energy of association of the enzyme-inhibitor complex.
已确定番茄果实中一种含37个残基的羧肽酶抑制剂的氨基酸序列。通过用焦谷氨酸氨肽酶消化还原型和S-羧甲基化的抑制剂，表明氨基末端为2-氧代吡咯烷-5-羧酸。序列的其余部分通过分析在酸性条件下于Asp4-Pro5键处特异性切割产生的肽段以及用胰蛋白酶处理产生的肽段来确定。该抑制剂的氨基酸序列与来自马铃薯的类似抑制剂在26个位置相同，且其中两个替换是高度保守的。已利用非保守替换的鉴定来更好地界定抑制剂中据信对酶-抑制剂复合物结合自由能贡献不大的区域。
