カキの糖代謝に関する基礎的検討ヘキソキナーゼの性状と同酵素に対する水銀化合物の影響

概要

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In an attempt to elucidate the mode of life of oyster, an important product of Hiroshima Prefecture, from biochemical viewpoints as the base of studies on the effect of pollutants on oyster, enzymological properties of hexokinase, a rate-limiting enzyme of glucose metabolism, were examined in relation to glycogenesis. It is worth noting that the amount of glycogen in oyster increased markedly from winter to spring and decreased abruptly from spring to summer. Oyster hexokinase was partially purified about 30 times by ammonium sulfate fractionation and DEAE-Sephadex A-50 column chromatography. Cellulose acetate membrane electrophoresis of this partially purified preparation of oyster hexokinase revealed a band with the mobility similar to that of mammalian hexokinase type II. The K_m values of oyster hexokinase for D-glucose and ATP were 4.9×10^<-5> and 1.6×10^<-4>M, respectively. Oyster hexokinase activity was inhibited by 30-40% by 400 nM methylmercuric chloride competitively with respect to D-glucose and in a mixed-type manner with respect to ATP. These results indicated the similarity of enzymological properties of oyster hexokinase to those of mammalian hexokinase type II. Significance of the existence of type II-like hexokinase was discussed in reference to the regulation of glucose metabolism and sensitivity to SH-inhibitors such as mercury, etc.
公益社団法人日本薬学会の論文
1980-08-31