Distribution of digestive proteinases in the alimentary tract of the european corn borerOstrinia nubilalis (lepidoptera: Pyralidae)

Autor: Phak-San Chin, Jon G. Houseman
Rok vydání: 1995
Předmět:
Zdroj: Archives of Insect Biochemistry and Physiology. 28:103-111
ISSN: 1520-6327
0739-4462
DOI: 10.1002/arch.940280202
Popis: The distribution of digestive proteinases in either the anterior and posterior midgut or between the midgut epithelium and ectoperitrophic and endo-peritrophic spaces in the midgut were examined in the European corn borer, Ostrinia nubilalis. Trypsin, chymotrypsin, elastase, and aminopeptidase activities were the same in the anterior and posterior halves of the midgut. Of the total aminopeptidase activity, 95% was located in the midgut epithelium, and 90% of the trypsin, 97% of chymotrypsin, and 93% of the elastase activity were found in the midgut lumen. Trypsin, measured by hydrolysis of benzoyl-L-arginine ethyl ester, and chymotrypsin levels were significantly higher in the ectoperitrophic space compared to the endoperitrophic space. Digestion in the midgut is proposed to be sequential with tryptic digestion occurring in the endoperitrophic space. Ingested protein is digested further in the ectoperitrophic space by the action of elastase, chymotrypsin, and a second trypsin. Final digestion occurs by an intracellular aminopeptidase. © 1995 Wiley-Liss, Inc.
Databáze: OpenAIRE
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