ISSN:
1432-072X
Keywords:
l-glutamine-d-fructose-6-phosphate aminotransferase
;
Chitin synthase
;
Chitin
;
Candida albicans
;
Germ-tube formation
;
Dimorphism
;
Polyoxin D
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The synthesis of chitin during germ-tube formation in Candida albicans may be regulated by the first and last steps in the chitin pathway: namely l-glutamine-d-fructose-6-phosphate aminotransferase and chitin synthase. Induction of germ-tube formation with either glucose and glutamine or serum was accompanied by a 4-fold increase in the specific activity of the aminotransferase. Chitin synthase in C. albicans is synthesized as a proenzyme. N-acetyl glucosamine increased the enzymic activity of the activated enzyme 3-fold and the enzyme exhibited positive co-operativity with the substrate, UDP-N-acetylglucosamine. Although chitin synthase was inhibited by polyoxin D (K i =1.2μM) this antibiotic did not affect germination. During germ-tube formation the total chitin synthase activity increased 1.4-fold and the expressed activity (in vivo activated proenzyme) increased 5-fold. These results could account for the reported 5-fold increase in chitin content observed during the yeast to mycelial transformation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00403204
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