ISSN:
1432-072X
Keywords:
Phycomyces
;
Chitin synthetase
;
Germination
;
Proteolytic activation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The chitin synthetase of Phycomyces blakesleeanus mycelium is a particulate enzyme sedimenting mostly at 1000xg. The activity in crude extracts or cellular fractions can be increased more than tenfold by mild trypsin treatment. Plotting the reaction velocity versus UDP-N-acetylglucosamine concentration yields a sigmoidal curve. N-acetylglucosamine, which greatly stimulates the enzyme, changes the kinetics to an almost normal hyperbolic relationship. The enzyme is nearly absent in dormant spores and is synthesized “de novo” in germinating spores (from 4 h germination on). Trypsin treatment of extracts from germinating spores to assay the synthesis of the proenzyme did not reveal an earlier synthesis of the zymogen, which therefore might have some activity of its own.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00406034
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