Hui K S, Weiss B, Hui M, Lajtha A
J Neurosci Res. 1977;3(3):231-9. doi: 10.1002/jnr.490030306.
Calf brain prolidase covalently bound to CNBr-Sepharose 4B, retained about 32% of the activity of the uncoupled enzyme. The free enzyme showed slightly greater stability than the bound preparation when stored at 20 degrees C or at 0 degrees C. However, in either case the free and bound enzymes were more stable at the lower temperature. Greater thermal stability was shown by the free enzyme than by the bound preparation over a temperature range of 25 degrees C-60 degrees C. The free and bound prolidase, with and without Mn+2, had maximal activity at pH 4.0. Although the bound enzyme showed a single maximum, the free preparation exhibited three pH maxima of 4.0, 9.0, and 6.5, in decreasing order of activity. The ions Ag+, Cu+, Hg+2, and Zn+2 were strongly inhibitory on the free enzyme, whereas inhibition of the bound enzyme, with the exception of Zn+2 , was less. Unlike the coupled enzyme, a stimulatory effect was obtained on the free preparation with Co+3, Mg+2, and Mn+2. Various other compounds were studied and their effects were noted.
共价结合到溴化氰-琼脂糖4B上的小牛脑脯氨酰肽酶保留了未偶联酶约32%的活性。当在20℃或0℃储存时，游离酶比结合制剂表现出稍高的稳定性。然而，在任何一种情况下，游离酶和结合酶在较低温度下都更稳定。在25℃至60℃的温度范围内，游离酶比结合制剂表现出更高的热稳定性。游离和结合的脯氨酰肽酶，无论有无Mn+2，在pH 4.0时都具有最大活性。虽然结合酶表现出单一的活性最大值，但游离制剂呈现出三个pH最大值，分别为4.0、9.0和6.5，活性依次降低。Ag+、Cu+、Hg+2和Zn+2离子对游离酶有强烈抑制作用，而除Zn+2外，对结合酶的抑制作用较小。与偶联酶不同，Co+3、Mg+2和Mn+2对游离制剂有刺激作用。研究了各种其他化合物并记录了它们的作用。
