title: A soluble exopolyphosphatase of Saccharomyces cerevisiae. Purification and characterization.
abstract: A soluble polyphosphatase of Saccharomyces cerevisiae, purified to apparent homogeneity, is monomeric with a molecular mass of 40 kDa. It acts as an exoenzyme in a processive mode releasing orthophosphate residues from long polyphosphate chains until pyrophosphate is reached. Polyphosphates of all the lengths examined are used as substrates with a preference for those of about 250 residues. These are degraded with a kcat/Km near the limit for diffusion-controlled reactions. At 37 degrees C, the enzyme releases about 500 phosphate residues/s. It does not act on pyrophosphate, ATP, or the cyclic form of tripolyphosphate. For optimal activity the enzyme requires magnesium, manganese, or cobalt.
authors.affiliation: Department of Biochemistry, Stanford University School of Medicine, California 94305-5307.
authors.forename: H
authors.initials: H
authors.lastname: Wurst
authors.forename: A
authors.initials: A
authors.lastname: Kornberg
mesh_terms: D017766:Acid Anhydride Hydrolases / Q000302:isolation & purification* / Q000378:metabolism*; D002413:Cations, Divalent / Q000494:pharmacology; D002845:Chromatography; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D017886:Durapatite; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008970:Molecular Weight; D009994:Osmolar Concentration; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013095:Spermidine / Q000494:pharmacology; D013379:Substrate Specificity; D013816:Thermodynamics
chemical_list: D002413:Cations, Divalent; D017886:Durapatite; D017766:Acid Anhydride Hydrolases; C020137:exopolyphosphatase; D013095:Spermidine