Properties of Partially Purified Endopolyphosphatase of the Yeast Saccharomyces cerevisiae

---

L. P. Lichko^*, T. V. Kulakovskaya, and I. S. Kulaev

Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, pr. Nauki 5, 142290 Pushchino, Moscow Region, Russia; fax: (495) 956-3370; E-mail: alla@ibpm.pushchino.ru

^* To whom correspondence should be addressed.

Received June 28, 2010; Revision received July 7, 2010

---

Partially purified endopolyphosphatase from cytosol of the yeast Saccharomyces cerevisiae with inactivated genes PPX1 and PPN1 encoding exopolyphosphatases was obtained with ion-exchange and affinity chromatography. The enzyme activity was estimated by decrease of polyphosphate chain length determined by PAGE. The enzyme cleaved inorganic polyphosphate without the release of orthophosphate (P_i) and was inhibited by heparin and insensitive to fluoride. Mg²⁺, Mn²⁺, and Co²⁺ (1.5 mM) stimulated the activity, and Ca²⁺ was ineffective. The molecular mass of the endopolyphosphatase determined by gel filtration was of ~20 kDa.

---

KEY WORDS: inorganic polyphosphates, endopolyphosphatase, exopolyphosphatase, cytosol, PPX1 and PPN1 mutants, Saccharomyces cerevisiae

DOI: 10.1134/S0006297910110131

---