Induction and Partial Characterization of Antibacterial Proteins in the Hemolymph of the Silkworm, Bombyx Mori

Abstract

The injection of live or heat-killed bacteria into larvae of trie silkworm, Bombyx mori, induced antibacterial activity in the hemolymph. A wide variety of gram-negative and gram-positive bacteria were effective as inducing agents, but saline alone, yeast cells and fungal spores were not effective. The antibacterial activities were separated into six bands on native polyacrylamide gel electrophoresis, which were sensitive to trypsin. Some of these antibacterial proteins were partially purified by CM-cellulose column chromatography. The proteins were heat-stable and showed no lysozyme activity. The proteins repressed the growth of various gram-positive and gram-negative bacteria. © 1988, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.