Abstract

A localization of charged and hydrophobic amino acid residues in the trypsin molecule was studied, and a percentage of the amino acids of different types on a surface of the enzyme globule was determined. The charged and hydrophobic amino acid residues were shown to be irregularly distributed on the protein surface and to form local clusters. The VION KN-1 and VION AN-1 fibers and chitosan were found to be promising carriers for the trypsin immobilization, because an adsorption on these fibers provided the preservation of 54, 58 and 65% of the catalytic activity of the native enzyme in solution, respectively (measured according to the hydrolysis rate of the bovine serum albumin). The IR spectra of the native (free) enzyme and the enzyme immobilized on the polymeric supports were analyzed. Electrostatic interactions and hydrogen bonds were shown to be dominant during the trypsin adsorption on the VION fibers. Carboxyl groups of the VION KN-1 interacted with positively charged regions of the molecule which contained His, Lys, and Arg. A large number of amino groups of the VION AN-1 and chitosan created an excessive positive charge which, possibly, provided a binding to the negatively charged Asp and Glu. However, hydrophobic interactions in which Gly, Ala, Tyr, Val, Phe, Pro, and Leu were involved became the most important for the trypsin adsorption on chitosan.

中文翻译：

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胰蛋白酶与离子交换纤维和壳聚糖相互作用过程的研究

摘要

研究了胰蛋白酶分子中带电和疏水性氨基酸残基的定位，并确定了酶球表面上不同类型氨基酸的百分比。显示带电和疏水性氨基酸残基不规则地分布在蛋白质表面并形成局部簇。发现 VION KN-1 和 VION AN-1 纤维和壳聚糖是胰蛋白酶固定化的有希望的载体，因为这些纤维上的吸附使溶液中天然酶的催化活性保持了 54%、58% 和 65% ，分别（根据牛血清白蛋白的水解率测定）。分析了天然（游离）酶和固定在聚合物载体上的酶的红外光谱。在 VION 纤维上的胰蛋白酶吸附过程中，静电相互作用和氢键占主导地位。VION KN-1 的羧基与分子中含有 His、Lys 和 Arg 的带正电荷区域相互作用。VION AN-1 和壳聚糖的大量氨基产生过多的正电荷，这可能与带负电荷的 Asp 和 Glu 结合。然而，Gly、Ala、Tyr、Val、Phe、Pro 和 Leu 参与的疏水相互作用成为胰蛋白酶在壳聚糖上吸附的最重要因素。VION AN-1 和壳聚糖的大量氨基产生过多的正电荷，这可能与带负电荷的 Asp 和 Glu 结合。然而，Gly、Ala、Tyr、Val、Phe、Pro 和 Leu 参与的疏水相互作用成为胰蛋白酶在壳聚糖上吸附的最重要因素。VION AN-1 和壳聚糖的大量氨基产生过多的正电荷，这可能与带负电荷的 Asp 和 Glu 结合。然而，Gly、Ala、Tyr、Val、Phe、Pro 和 Leu 参与的疏水相互作用成为胰蛋白酶在壳聚糖上吸附的最重要因素。