de Médicis E, Bergeron L
Can J Biochem. 1975 Oct;53(10):1101-5. doi: 10.1139/o75-151.
A kinetic study of procine chymotrypsin A-pi revealed two characteristic properties of this type of chymotrypsin: 1. Porcine chymotrypsin A-pi, like bovine chymotrypsin B-pi does not bind proflavin, which is a competitive inhibitor of bovine trypsin and chymotrypsin A-alpha. 2. The pH profiles of the steady-state parameters show the two usual important pK's. The basic one, pK2 = 9.6, affects both Km and kcat/Km and probably controls the binding conformation of chymotrypsin. The acidic one, pK1 = 5.7, affects kcat and kcat/Km and plays a role in the catalytic process. The value of pK1 is unusually low.
对猪胰凝乳蛋白酶A-π的动力学研究揭示了这类胰凝乳蛋白酶的两个特性：1. 猪胰凝乳蛋白酶A-π，如同牛胰凝乳蛋白酶B-π一样，不结合原黄素，原黄素是牛胰蛋白酶和胰凝乳蛋白酶A-α的竞争性抑制剂。2. 稳态参数的pH曲线显示出两个常见的重要pK值。碱性的pK2 = 9.6，同时影响Km和kcat/Km，可能控制着胰凝乳蛋白酶的结合构象。酸性的pK1 = 5.7，影响kcat和kcat/Km，并在催化过程中起作用。pK1的值异常低。
