The secreted aspartate proteinase of Candida albicans: physiology of secretion and virulence of a proteinase-deficient mutant.
It was established that Candida albicans grew rapidly in a simple medium containing yeast extract (0.2%, w/v) plus glucose (2%, w/v). These cultures were in or near to a state of nitrogen limitation and the concentration of secreted aspartate proteinase increased rapidly (within 3-4 h) on addition of BSA. Synthesis and secretion were apparently controlled both positively (induction by albumin or, more probably, the peptides produced from it) and negatively (repression by NH4Cl). A small intracellular pool of the enzyme was detected during production of the enzyme and this pool decreased with the cessation of synthesis and secretion. A stable mutant, IR24, was isolated which secreted less than 0.3% of the amount of the proteinase exported by the parent strain ATCC 10261. The LD50 values for mutant IR24 and the parent strain administered intravenously to mice were greater than 1.0 x 10(9) and 1.6 x 10(6) c.f.u. kg-1 respectively.
Department of Biochemistry, University of Otago, Dunedin, New Zealand.
I K
IK
Ross
F
F
De Bernardis
G W
GW
Emerson
A
A
Cassone
P A
PA
Sullivan
D000818:Animals; D016282:Aspartic Acid Endopeptidases; D002176:Candida albicans / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D002177:Candidiasis / Q000378:metabolism / Q000473:pathology; D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D007928:Lethal Dose 50; D051379:Mice; D008815:Mice, Inbred Strains; D009154:Mutation; D014774:Virulence
D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases