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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.

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