Journal ArticleDOI
Integumental chitin synthase activity in cell-free extracts of larvae of the Australian sheep blowfly, Lucilia cuprina, and two other species of diptera.
IF Turnbull,AJ Howells +1 more
Reads0
Chats0
TLDR
This is the first report of a cell-free chitin-synthesizing system derived from insect tissue which is sensitive to inhibition by diflubenzuron, and some radioactivity also becomes incorporated into non-chitin products in this system.Abstract:
Chitin synthase activity has been demonstrated in crude homogenates of larval integuments from L. cuprina and in similar preparations from Musca domestica and Calliphora erythrocephala. This is the first report of an insect integumental chitin synthase. This activity brings about the incorporation of radioactivity from UDP-N-acetyl-[14C]glucosamine into an ethanol- and alkali-insoluble form. A major part of this labelled product has been characterized as chitin by its insolubility in alkali, resistance to degradation by proteases and its susceptibility to digestion by chitinase and RCI. Most of the radioactivity solubilized during digestion by chitinase co-migrates with N-acetylglucosamine, glucosamine and chitobiose during paper chromatography. Some radioactivity also becomes incorporated into non-chitin products in this system. There is substantial evidence that incorporation is not brought about by whole epidermal cells or by microbial contamination in the homogenates. The extent of incorporation obtained with the homogenates is limited by the presence of degradative enzymes which rapidly break down the substrate (UDP-N-acetylglucosamine). The incorporation was partially inhibited (50-70%) by both polyoxin-D (apparent Ki 0'04I1M) and diftubenzuron (apparent Ki 5-8 11M). This is the first report of a cell-free chitin-synthesizing system derived from insect tissue which is sensitive to inhibition by diftubenzuron.read more
Citations
More filters
Journal ArticleDOI
Chitin metabolism in insects: structure, function and regulation of chitin synthases and chitinases
Hans Merzendorfer,Lars Zimoch +1 more
TL;DR: This review of recent advances in understanding chitin synthesis and its degradation in insects will summarize recent advances.
Journal ArticleDOI
Insect chitin synthases: a review.
TL;DR: Recent advances in elucidating the structure, regulation and function of insect chitin synthases as they relate to what is known about fungal chit in synthases and other glycosyltransferases are summarized.
Journal ArticleDOI
Insect chitin: Physical state, synthesis, degradation and metabolic regulation
Journal ArticleDOI
Chitin synthesis inhibitors: old molecules and new developments.
TL;DR: This review summarizes the latest advances on the mode of action of chitin synthesis inhibitors with a special focus on those molecules that act on a postcatalytic step of ch itin synthesis.
Related Papers (5)
Pesticides: insecticides and fungicides are chitin synthesis inhibitors.
Dietary TH 6040 alters composition and enzyme activity of housefly larval cuticle
Isaac Ishaaya,John E. Casida +1 more