Yokosawa H, Ishii S
J Biochem. 1977 Mar;81(3):657-63. doi: 10.1093/oxfordjournals.jbchem.a131501.
The reactivities of the active-site histidine residue in bovine trypsin and its anhydro-derivative, as well as in Streptomyces griseus trypsin and its anhydro-derivative have been compared. The reactivity with TLCK was found to be lost in both of the anhydrotrypsins. On the other hand, alkylation by iodoacetamide either in the presence or absence of 1-methylguanidine proceeded faster in anhydrotrypsins than in trypsins. These differential responses to alkylating reagents are discussed in terms of a subtle change in the active-site conformation which occurs during the conversion of trypsin into anhydrotrypsin. The examination of difference CD spectra, produced by interaction with benzamidine or beta-naphthamidine, also suggested a conformational difference of the active-site between the proteins of bovine origin.
已对牛胰蛋白酶及其脱水衍生物，以及灰色链霉菌胰蛋白酶及其脱水衍生物中活性位点组氨酸残基的反应活性进行了比较。发现两种脱水胰蛋白酶与甲苯磺酰-L-赖氨酸氯甲基酮（TLCK）的反应活性均丧失。另一方面，无论有无1-甲基胍存在，碘乙酰胺对脱水胰蛋白酶的烷基化反应都比对胰蛋白酶的反应进行得更快。根据胰蛋白酶转化为脱水胰蛋白酶过程中活性位点构象的细微变化，讨论了对烷基化试剂的这些差异反应。通过与苯甲脒或β-萘甲脒相互作用产生的差示圆二色光谱检查也表明，牛源蛋白质之间活性位点的构象存在差异。
