A mannoglucokinese of Mycobacterium tuberculosis H37Ra.
An ATP: D-glucose and D-mannose 6-phosphotransferase activity was found in Mycobacterium tuberculosis HERa. The activity was separated from other ATP- and polyphosphate D-glucose phosphotransferases in a procedure involving precipitation with ammonium sulfate, treatment with calcium phosphate gel, DEAE-cellulose and DEAE-Sephadex A50 chromatography. The optimum pH of the phosphorylation reaction was from 9 to 10.5. The hexokinase phosphorylated D-glucose with a Km of 20 mM under conditions of MgATP saturation. The Km for MgATP was 0.2 mM. The enzyme showed a higher activity on D-mannose at a saturation level being about 100-fold lower than that of D-glucose; it did not utilize either D-fructose or D-glucosamine. Inorganic poly(P) could not replace ATP as the phosphate donor. M. tuberculosis H37Ra was unable to grow on D-mannose which may suggest that the enzyme studied is involved in endogenous metabolism of this sugar.
Department of Biochemistry, Medical School, Lubartowska 85, 20-123 Lublin, Poland.
H
H
Kowalska
I
I
Pastuszak
M
M
Szymona
D000255:Adenosine Triphosphate / Q000494:pharmacology; D005591:Chemical Fractionation; D002852:Chromatography, Ion Exchange; D003067:Coenzymes / Q000494:pharmacology; D004795:Enzyme Stability; D005632:Fructose / Q000378:metabolism; D005944:Glucosamine / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009169:Mycobacterium tuberculosis / Q000201:enzymology*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D011122:Polyphosphates / Q000378:metabolism; D013379:Substrate Specificity
D003067:Coenzymes; D011122:Polyphosphates; D005632:Fructose; D000255:Adenosine Triphosphate; D017853:Phosphotransferases (Alcohol Group Acceptor); C485979:polyphosphate ATP-glucomannokinase; D005944:Glucosamine