[Characteristics of polyphosphatase activity of vacuoles in Saccharomyces cerevisiae cells].
Vacuoles of the Saccharomyces cerevisiae yeast possess a polyphosphatase activity which differs from other known vacuolar phosphohydrolase activities by pH-optimum, sensitivity towards inhibitors and distribution between the tonoplast and vacuolar sap. The polyphosphatase activity is inhibited by EDTA, molybdate, ortho-vanadate and fluoride. Nearly 77% of this activity is located in the vacuolar sap, while 25%--in the tonoplast fraction. Both the soluble and membrane-bound polyphosphatase activities are maximal at pH 6.8-7.2. Bivalent metal cations stimulate this activity in the following order: Zn2+ > Mg2+ > Co2+ > Mn2+. Other ions (Fe2+, Cu2+, Ca2+) inhibit this activity at all concentrations tested. The polyphosphatase activity of both the vacuolar sap and the tonoplast increases 2.4-and 2-fold, respectively, with an increase in the degree of substrate polymerization--from n = 3 to n = 208.
Andreeva
N A
NA
Lichko
L P
LP
Kulakovskaia
T V
TV
Okorokov
L A
LA
D002413:Cations, Divalent; D002462:Cell Membrane / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D014617:Vacuoles / Q000201:enzymology*
D002413:Cations, Divalent; D010744:Phosphoric Monoester Hydrolases