title: Identification, purification, and characterization of a D-arabinitol-specific dehydrogenase from Candida tropicalis.
abstract: A novel D-arabinitol (DA) dehydrogenase was identified and purified more than 300-fold from Candida tropicalis. The enzyme is specific for DA and catalyzes the NAD(+)-dependent oxidation at carbon 4 to yield D-ribulose. Purification was accomplished by a combination of protamine sulfate and ammonium sulfate precipitation and dye ligand chromatography on a reactive yellow 86 column. The apparent Km of the enzyme for DA ([NAD+] = 2.2 mM) is 39.8 mM. The apparent Km for NAD+ ([DA] = 384 mM) is 0.12 mM. The pH-optimum for the enzymatic oxidation of DA is approximately 10. Cofactor stereospecificity studies demonstrate that the enzyme catalyzes transfer of the 4(S) hydrogen of NADH with D-ribulose as substrate. The polyol substrate specificity of the present DA dehydrogenase makes the enzyme potentially useful for the development of a simple and specific method for the measurement of DA, a metabolite of pathogenic Candida spp. which has been described as a marker for disseminated candidiasis.
authors.affiliation: Syva Company, Research Department, Palo Alto, CA 94304.
authors.forename: M W
authors.initials: MW
authors.lastname: Quong
authors.forename: C G
authors.initials: CG
authors.lastname: Miyada
authors.forename: A C
authors.initials: AC
authors.lastname: Switchenko
authors.forename: T C
authors.initials: TC
authors.lastname: Goodman
mesh_terms: D002175:Candida / Q000201:enzymology*; D002458:Cell Fractionation; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D013237:Stereoisomerism; D013379:Substrate Specificity; D013401:Sugar Alcohol Dehydrogenases / Q000302:isolation & purification* / Q000378:metabolism*; D014461:Ultracentrifugation
chemical_list: D013401:Sugar Alcohol Dehydrogenases; C022751:D-arabinitol dehydrogenase