Abstract

Lysozyme adsorption complexes with graphene oxide (GO) and reduced GO were studied by means of radiotracer method using tritium as a label. The experiment includes adsorption study, with amount and enzymatic activity control, and revealing structural peculiarities of lysozyme adsorbed on graphene oxide surface by analysis of tritium distribution in the amino acid residues after the bombardment with atomic tritium. Experimental and molecular docking results suggested that lysozyme adsorbs directly on GO by formation of bonds between GO surface and Cys6 and Arg128 that contribute to formation conformation, in which aromatic residues forms π-π bonds with GO surface, and positively charged amino acid residues bind with O-containing groups of GO via electrostatic attraction. In the follow-up layers lysozyme molecules interact with each other that result in changes and adsorbed lysozyme molecules resulting in changes in protein structure. Such changes are not critically significant but lead to increase of availability of an active site of the enzyme for binding with a substrate after the desorption from the multilayer.

摘要

使用氚作为标记，通过放射性示踪法研究了溶菌酶与氧化石墨烯（GO）和还原GO的吸附复合物。实验包括吸附研究，控制量和酶活性，通过分析原子氚轰击后氨基酸残基中氚的分布，揭示溶菌酶吸附在氧化石墨烯表面的结构特性。实验和分子对接结果表明溶菌酶通过 GO 表面与 Cys6 和 Arg128 之间形成键直接吸附在 GO 上，这有助于形成构象，其中芳香族残基与 GO 表面形成 π-π 键，带正电荷的氨基酸残基与GO 的含 O 基团通过静电吸引。在后续层中，溶菌酶分子相互相互作用导致变化，吸附的溶菌酶分子导致蛋白质结构发生变化。这种变化不是非常重要，但会导致酶的活性位点在从多层解吸后与底物结合的可用性增加。