V. F. Sivuk1, I. M. Rusina2, T. A. Luchko1, A. F. Makarchikov1,2
Soluble nucleoside triphosphatase differing in its properties from all known proteins with NTPase activity was partially purified from bovine kidneys. The enzyme has pH optimum of 7.5, molecular mass of 60 kDa, as estimated by gel chromatography, and shows an absolute dependence on divalent metal ions. NTPase obeyed Michaelis-Menten kinetics in the range of substrate concentration tested from 45 to 440 µM; the apparent Km for inosine-5?-triphosphate was calculated to be 23.3?µM. The enzyme was found to possess a broad substrate specificity, being capable of hydrolyzing various nucleoside-5?-tri- as well as diphosphates.
Key words: nucleoside triphosphatase, substrate specificity, kinetic properties, bovine kidney.
The original article in Russian is available for download in PDF format.
© The Ukrainian Biochemical Journal