Drozdz R, Naskalski J W, Sznajd J
Department of Biochemical Diagnostics, N. Copernicus Academy of Medicine, Kraków, Poland.
Acta Biochim Pol. 1988;35(4):277-86.
The enzyme system composed of human neutrophilic myeloperoxidase (H2O2-oxidoreductase, EC 1.11.1.7), H2O2 and Cl-, at pH 4.5 interacts with egg white lysozyme (EC 3.2.1.17) in several stages. In the first stage, occurring at lysozyme to H2O2 molar ratio of 1:1.4-1.8, the lysozyme loses its enzyme activity but does not yield any derivative distinguishable from the native protein on polyacrylamide gel electrophoresis (PAGE). The second stage of oxidation begins at lysozyme to H2O2 molar ratio above 1:5, producing a change in the lysozyme spectrum at 260-290 nm, and yielding protein derivatives with molecular masses equal to multiples of 14.3 kDa, i.e. the lysozyme molecular mass. This implies that an excessive oxidation of lysozyme by the myeloperoxidase-H2O2-Cl- system produces cross-linking of lysozyme molecules to di-, tri-, tetra-, and pentameric structures. At lysozyme to H2O2 molar ratio exceeding 1:12 a water insoluble white product, which consists of a set of lysozyme cross-linked derivatives, is obtained.
由人嗜中性粒细胞髓过氧化物酶（H2O2-氧化还原酶，EC 1.11.1.7）、H2O2和Cl-组成的酶系统，在pH 4.5时与蛋清溶菌酶（EC 3.2.1.17）分几个阶段相互作用。在第一阶段，当溶菌酶与H2O2的摩尔比为1:1.4 - 1.8时发生，溶菌酶失去其酶活性，但在聚丙烯酰胺凝胶电泳（PAGE）上没有产生任何与天然蛋白质不同的衍生物。氧化的第二阶段在溶菌酶与H2O2的摩尔比高于1:5时开始，在260 - 290 nm处溶菌酶光谱发生变化，并产生分子量等于14.3 kDa倍数（即溶菌酶分子量）的蛋白质衍生物。这意味着髓过氧化物酶 - H2O2 - Cl-系统对溶菌酶的过度氧化会导致溶菌酶分子交联形成二聚体、三聚体、四聚体和五聚体结构。当溶菌酶与H2O2的摩尔比超过1:12时，会得到一种水不溶性白色产物，它由一组溶菌酶交联衍生物组成。
