Midgut proteinases of the cockroachNauphoeta cinerea

Autor: Elena N. Elpidina, D. P. Zhuzhikov, V. A. Gromenko, Ya. E. Dunaevskii, K. S. Vinokurova, Yu. A. Rudenskaya
Rok vydání: 2000
Předmět:
Zdroj: Journal of Evolutionary Biochemistry and Physiology. 36:375-383
ISSN: 1608-3202
0022-0930
Popis: The study of properties of proteolytic enzymes in midgut of imago of the cockroachNauphoeta cinerea Oliv. Has been carried out. It is shown that the total proteolytic activity of digestive proteases, measured with azocasein as substrate, is maximal at pH 11.5 both in the anterior and in the posterior parts of the midgut. The predominant part of this activity (67%) was present in the posterior part. Fractionation of preparation from the posterior part on a column with Sephadex G-50 and subsequent analysis of the activity in the obtained fractions using specificp-nitroanilide substrates and effects of activators and inhibitors of active center have allowed revealing three types of activity of serine proteinases and one cysteine proteinase. No activity of aspartic and metalloproteinases were detected. Among serine proteinases, one trypsin-like, one unusual SHdependent serine, one chymotrypsin-like, and not less than two enzymes hydrolyzing specific substrate of subtilisin were established. The fractionation of the preparation from the anterior part has allowed revealing only three proteinases that were similar by their properties to cysteine, SHdependent serine, and chymotrypsin-like ones in the posterior part of midgut. Their activity was lower in the anterior, than in the posterior part of the midgut. The probable causes of the low proteolytic activity in the anterior part of the midgut are discussed.
Databáze: OpenAIRE
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