Larionova I I, Kazanskaia N F, Sakharov I Iu
Biokhimiia. 1979 Feb;44(2):350-8.
The effects of electrostatic charge of the matrix on the pH-dependence of interactions of commercial trypsin with preparations of pancreatic inhibitor modified by soluble polysaccharide coupling were studied. It was shown that the rate constants of trypsin association with native and modified pancreatic inhibitor preparations as well as the rate constants of dissociation of their complexes and, consequently, the inhibition constants are identical. The invariability of the rate constants for the association reaction after the increase in the molecular weight of pancreatic inhibitor may be probably accounted for by the fact that the limiting step of a stable trypsin-inhibitor complex formation is not controlled by diffusion. Thermal denaturation of pancreatic inhibitor preparations modified by binding to polysaccharides (pH 4.7--8.0, 97 degrees C) suggests an essential role of the negative charge of matrix in stabilization of the protein inhibitor globule.
研究了基质静电荷对商业胰蛋白酶与经可溶性多糖偶联修饰的胰腺抑制剂制剂相互作用的pH依赖性的影响。结果表明，胰蛋白酶与天然和修饰的胰腺抑制剂制剂结合的速率常数以及它们复合物的解离速率常数，进而抑制常数是相同的。胰腺抑制剂分子量增加后缔合反应速率常数的不变性可能是由于稳定的胰蛋白酶-抑制剂复合物形成的限速步骤不受扩散控制。通过与多糖结合修饰的胰腺抑制剂制剂的热变性（pH 4.7 - 8.0，97℃）表明基质的负电荷在稳定蛋白质抑制剂球体中起重要作用。
