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Beck, E; Wieczorek, J; Reinecke, W: Purification and properties of hamamelosekinase, European Journal of Biochemistry, 107, 485-489 (1980), doi:10.1111/j.1432-1033.1980.tb06054.x
Abstract:
Hamamelosekinase (ATP: hamamelose 21‐phosphotransferase) was purified from a crude extract of Kluyvera citrophila 627 (Enterobacteriaceae) which has been grown on d ‐hamamelose. Ammonium‐sulfate fractionation and twofold chromatography on DEAE‐cellulose resulted in a 51‐fold purification of the enzyme. Neither glucosekinase nor significant ATPase activity could be detected in the pure preparation. Besides d ‐hamamelose only d ‐hamamelitol was utilized as a substrate; however, the latter was phosphorylated at a very low rate. The molecular weight of the enzyme as estimated by gel chromatography is 21000. The K m values for hamamelose and ATP were 3 mM and 2.5 mM, respectively. The pH optimum was found at 7.5. In contrast to hexokinase, purified hamamelosekinase is very labile and could only be stabilized by addition of its substrate d ‐hamamelose. The most unusual property with respect to yeast hexokinase is a pronounced substrate inhibition by hamamelose (> 5 mM) and ATP (> 7 mM), respectively, which could be interpreted as due to an economic utilization of the nutrient. Hamamelosekinase as well as glucosekinase are inducible by growing the microorganisms on the corresponding monosaccharides.

Letzte Änderung 23.06.2020