RT Journal Article SR Electronic(1) A1 de Rousset-Hall, Anne A1 Gooday, G. W.YR 1975 T1 A Kinetic Study of a Solubilized Chitin Synthetase Preparation from Coprinus cinereus JF Microbiology, VO 89 IS 1 SP 146 OP 154 DO https://doi.org/10.1099/00221287-89-1-146 PB Microbiology Society, SN 1465-2080, AB SUMMARY: The solubilized chitin synthetase preparation from the stipes of Coprinus cinereus is activated by its substrate, UDP-N-acetylglucosamine, and by carbohydrates, in particular N-acetylglucosamine, diacetylchitobiose and glucose. Analysis of the results of variation in enzyme activity with UDP-GlcNAc concentration by several methods suggested that this substrate is an allosteric activator, with Hill coefficients close to 2 and 4 at concentrations above and below 0·1 mm respectively, and an [S]0·5 value of 0·9 mm. N-acetylglucosamine lessened but did not abolish the sigmoidal shape of the velocity-substrate concentration plot. The chitin synthetase was inhibited by adenine and uridine nucleotides, and uridine diphosphate was a powerful competitive inhibitor. The enzyme preparation also contained a nucleoside diphosphatase activity and the implications of the removal of the inhibitory UDP formed by the chitin synthetase are considered., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-89-1-146