Gaertner H F, Puigserver A J
Centre de Biochimie et de Biologie Moléculaire, CNRS, Marseille, France.
Enzyme Microb Technol. 1992 Feb;14(2):150-5. doi: 10.1016/0141-0229(92)90174-m.
The reaction of trypsin with activated monomethoxypoly(ethylene glycol) with various molecular masses led to the development of a series of poly(ethylene glycol)-modified trypsins (PEG-trypsins). On determining the catalytic properties of PEG-trypsin using N-benzoyl-L-arginine p-nitroanilide as a substrate, a three- to fourfold increase in the maximal velocity of hydrolysis was found to occur, whatever the size of the PEG moiety used. PEG-trypsin with higher molecular mass moieties showed lower Michaelis constant values. The activation of trypsin was neither reversed by nucleophiles such as hydroxylamine, nor prevented when modification was carried out in the presence of benzamidine or in the presence of the polypeptidic soybean trypsin inhibitor. Chemical modification of about 80% of the free amino groups with PEG chains significantly improved the resistance to heat and detergents. This might result from the formation of a highly hydrogen-bonded structure around the enzyme.
胰蛋白酶与具有不同分子量的活化单甲氧基聚（乙二醇）反应，从而开发出一系列聚（乙二醇）修饰的胰蛋白酶（PEG - 胰蛋白酶）。在用对硝基苯甲酰 - L - 精氨酸作为底物测定PEG - 胰蛋白酶的催化特性时，发现无论所用PEG部分的大小如何，水解最大速度都有三到四倍的增加。具有较高分子量部分的PEG - 胰蛋白酶显示出较低的米氏常数值。胰蛋白酶的活化既不能被亲核试剂如羟胺逆转，在苯甲脒存在下或多肽大豆胰蛋白酶抑制剂存在下进行修饰时也不会被阻止。用PEG链对约80%的游离氨基进行化学修饰显著提高了对热和洗涤剂的耐受性。这可能是由于在酶周围形成了高度氢键结合的结构。
