CHARACTERIZATION OF GLYCEROL KINASE AND NAD-INDEPENDENT GLYCEROL 3-PHOSPHATE DEHYDROGENASE FROM Pediococcus pentosaceus N5p

PASTERIS, S.E.; STRASSER DE SAAD, A.M.

LETTERS IN APPLIED MICROBIOLOGY

The Society for Applied Microbiology

Año: 1998 vol. 27 p. 93 - 97

0266-8254

The pathway involved in glycerol dissimilation in Pediococcus pentosaceus N5p, a strain isolated from wine, includes glycerol kinase and NAD-independent glycerol-3P dehydrogenase. The properties of these enzymes were studied. Glycerol kinase activity was maximal at 28 °C and pH 7·5 in 50 mmol l−1 Tris-HCl buffer. The end-products of the reaction acted as competitive inhibitors while fructose-1,6-diphosphate was a non-competitive inhibitor. Mg2+ was required for optimal enzyme activity. The Km values for both substrates were 0·11 and 0·37 mmol l−1 for glycerol and ATP, respectively. NAD-independent glycerol-3P dehydrogenase activity was maximal at 37 °C and pH 7·5 in 100 mmol l−1 Tris-HCl buffer. The enzymatic activity was activated by KCN and bivalent cations as Mg2+ and Ca2+, but it was strongly inhibited by others. Dihydroxyacetone phosphate acted as competitive inhibitor while ATP and phosphenolpyruvate were non-competitive inhibitors.