Inhibition of Saccharomyces cerevisiae phosphomannose isomerase by the NO-donor S-nitroso-acetyl-penicillamine.
Phosphomannose isomerase (PMI; EC. 5.3.1.8) is an essential metalloenzyme in the early steps of the protein glycosylation pathway in both prokaryotes and eukaryotes. The Cys150 residue (according to Candida albicans PMI numbering) is conserved in the active centre of mammalian and yeast PMI, but not in bacterial species where it is replaced by Asn. Here, the dose- and time-dependent inhibitory effect of the NO-donor S-nitroso-acetyl-penicillamine on the Saccharomyces cerevisiae PMI catalytic activity is reported. The analysis of the X-ray crystal structure of C. albicans PMI and of the molecular model of S. cerevisiae PMI provides a rationale for the low reactivity of Cys150 towards alkylating and nitrosylating agents.
Salvati
L
L
Dipartimento di Biologia, Università Roma Tre, Viale Guglielmo Marconi 446, I-00146 Roma, Italy.
Mattu
M
M
Tiberi
F
F
Polticelli
F
F
Ascenzi
P
P
D001665:Binding Sites; D004791:Enzyme Inhibitors / Q000378:metabolism / Q000494:pharmacology*; D008359:Mannose-6-Phosphate Isomerase / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D015394:Molecular Structure; D017434:Protein Structure, Tertiary; D026423:S-Nitroso-N-Acetylpenicillamine / Q000378:metabolism / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013997:Time Factors; D015032:Zinc / Q000378:metabolism
D004791:Enzyme Inhibitors; D026423:S-Nitroso-N-Acetylpenicillamine; D008359:Mannose-6-Phosphate Isomerase; D015032:Zinc