Larisa A. Chupova

Ph.D. (Chemistry)

Research fellow (Laboratory of biotechnology)

Phone: +7 (495) 336-68-33

Selected publications

  1. Chuvikovsky D.V., Esipov R.S., Skoblov Y.S., Chupova L.A., Muravyova T.I., Miroshnikov A.I., Lapinjoki S., Mikhailopulo I.A. (2006). Ribokinase from E. coli: expression, purification, and substrate specificity. Bioorg. Med. Chem. 14 (18), 6327–32 [+]

    Ribokinase (RK) was expressed in the Escherichia coli ER2566 cells harboring the constructed expression plasmid encompassing the rbsK gene, encoding ribokinase. The recombinant enzyme was purified from sonicated cells by double chromatography to afford a preparation that was ca. 90% pure and had specific activity of 75 micromol/min mg protein. Catalytic activity of RK: (i) is strongly dependent on the presence of monovalent cations (potassium>>>ammonium>cesium), and (ii) is cooperatively enhanced by divalent magnesium and manganese ions. Besides D-ribose and 2-deoxy-D-ribose, RK was found to catalyze the 5-O-phosphorylation of D-arabinose, D-xylose, and D-fructose in the presence of ATP, and potassium and magnesium ions; L-ribose and L-arabinose are not substrates for the recombinant enzyme. A new radiochemical method for monitoring the formation of D-pentofuranose-5-[32P]phosphates in the presence of [gamma-32P]ATP and RK is reported.

  2. Esipov R.S., Gurevich A.I., Chuvikovsky D.V., Chupova L.A., Muravyova T.I., Miroshnikov A.I. (2002). Overexpression of Escherichia coli genes encoding nucleoside phosphorylases in the pET/Bl21(DE3) system yields active recombinant enzymes. Protein Expr. Purif. 24 (1), 56–60 [+]

    The Escherichia coli genes encoding purine nucleoside phosphorylase, uridine phosphorylase, and thymidine phosphorylase were cloned into pET plasmids to generate highly effective E. coli BL21(DE3) strains producing each of these enzymes. Optimum conditions for biosynthesis of each enzyme as a soluble protein with intact biological activity were found. The crude preparations are approximately 80% pure and can be used immediately for enzymatic transglycosylation. The enzyme preparations were purified to homogeneity by two steps including fractional precipitation with ammonium sulfate and subsequent chromatography on Sephadex G-100 and DEAE-Sephacel.