致倦库蚊血淋巴中诱导型溶菌酶活性的表征

Characterization of inducible lysozyme activity in the hemolymph of Rhodnius prolixus.

Azambuja P, Garcia E S

Departamento de Biologia Geral, Universidade Federal Fluminense, Niterói, Brasil.

Braz J Med Biol Res. 1987;20(5):539-48.

Abstract

The characterization and partial purification of an induced lysozyme activity in the hemolymph of adult Rhodnius prolixus inoculated with Micrococcus lysodeikticus is described. 2. Little or no activity against M. lysodeikticus appeared in the first hours after inoculation, but the activity increased reaching a maximum 4 days later, which was maintained to day 12. 3. The activity was characterized as lysozyme on the basis of the following considerations: 1) pH optimum and thermostability at acidic pH; 2) rate of lysis negatively dependent on ionic strength; 3) binding to SP-Sephadex at pH 5.5; 4) apparent molecular weight of 15 kDal. 4. Crude or semi-purified enzyme preparations showed a high degree of stability during handling, freezing and thawing, and standing at 5 degrees C. 5. Incubation of abdominal fat bodies from treated insects resulted in the release of activity into the medium. 6. The relationship between induced lysozyme activity and its role as an insect defense mechanism is discussed.

摘要

本文描述了接种溶壁微球菌的成年南美锥蝽血淋巴中诱导型溶菌酶活性的特性及部分纯化过程。2. 接种后的最初几个小时内，对溶壁微球菌几乎没有活性，但活性在4天后增加到最大值，并维持到第12天。3. 根据以下因素，该活性被鉴定为溶菌酶：1）酸性pH下的最适pH值和热稳定性；2）裂解速率与离子强度呈负相关；3）在pH 5.5时与SP-葡聚糖凝胶结合；4）表观分子量为15 kDa。4. 粗酶制剂或半纯化酶制剂在处理、冷冻和解冻以及在5℃下放置期间表现出高度稳定性。5. 处理过的昆虫腹部脂肪体的孵育导致活性释放到培养基中。6. 讨论了诱导型溶菌酶活性与其作为昆虫防御机制的作用之间的关系。