A Study of the Complex of Proteolytic Enzymes and Their Protein Inhibitors in the Embryogenesis of the Silkworm

We studied changes in the activities of serin, thiol, and aspartyl proteinases and their protein inhibitors during embryogenesis of the silkworm. The dynamics of the activities of the protein inhibitors and specific proteinases were interrelated, thus providing for the coordination and fine regulation of the functioning of the proteolytic complex of enzymes during embryogenesis. Possible functions of peptidohydrolases and their protein inhibitors in the silkworm are discussed.     

Isolation,Purification, and Properties of Cysteine Proteinase from <Emphasis Type="Italic">Bombyx mori</Emphasis> L. Eggs

Silkworm moth (bombyx) egg cysteine proteinase with maximal activity at pH 3.0 was purified by chromatography and isoelectrofocusing. On SDS-electrophoresis in polyacrylamide gel the purified enzyme showed a single band of molecular mass 50 kD. Isoelectrofocusing revealed that the bombyx egg cysteine proteinase exists in two forms with pI values of 5.95 and 6.43, respectively. The enzyme activity was sensitive to inhibition by iodoacetamide and p-chloromercuribenzoate but resistant to EDTA, pepstatin, and phenylmethylsulfonyl fluoride. The cysteine proteinase hydrolyzes storage proteins of bombyx eggs but it was inactive with respect to N-benzoyl-D,L-arginine-p-nitroanilide (BAPNA). It is a cathepsin L-like enzyme.     

A study of the complex of proteolytic enzymes and their protein inhibitors in embryogenesis of the silkworm

We studied changes in the activities of serin, thiol, and aspartyl proteinases and their protein inhibitors during embryogenesis of the silkworm. The dynamics of activities of the protein inhibitors and specific proteinases were interrelated, thus providing for coordination and fine regulation of functioning of the proteolytic complex of enzymes during embryogenesis. Possible functions of peptidohydrolases and their protein inhibitors in the silkworm are discussed.