Pearson S D, Gan J C
Int J Biochem. 1985;17(11):1253-62. doi: 10.1016/0020-711x(85)90016-3.
Exposure of alpha 1-PI to nitrous acid resulted in a complete inactivation of either of its elastase or trypsin inhibitors activities. Amino acid analyses of the nitrous acid treated inhibitor revealed only losses of one tryphanyl and three lysyl residues. Reductive methylation of alpha 1-PI offered no protection against loss of activity by nitrous acid. Since no further loss of lysyl residues was observed upon exposure of fully active reductively methylated alpha 1-PI to nitrous acid, modification of one tryptophanyl residue appears to be responsible for the inhibitor's sensitivity to nitrous acid. Absorption spectral studies of the nitrous acid treated alpha 1-PI indicated that the tryptophanyl residue was modified to its N-nitroso derivative.
α1-抗胰蛋白酶（α1-PI）暴露于亚硝酸会导致其弹性蛋白酶或胰蛋白酶抑制活性完全丧失。对经亚硝酸处理的抑制剂进行氨基酸分析，结果显示仅一个色氨酸残基和三个赖氨酸残基缺失。α1-PI的还原甲基化并不能防止其因亚硝酸而丧失活性。由于将完全活性的还原甲基化α1-PI暴露于亚硝酸后未观察到赖氨酸残基进一步缺失，因此一个色氨酸残基的修饰似乎是该抑制剂对亚硝酸敏感的原因。对经亚硝酸处理的α1-PI进行的吸收光谱研究表明，色氨酸残基被修饰为其N-亚硝基衍生物。
