Kanda F, Kamikashi T, Ishibashi S
J Biochem. 1976 Mar;79(3):543-8. doi: 10.1093/oxfordjournals.jbchem.a131098.
A difference in the mode of inhibition of hexokinase [EC 2.7.1.1] isoenzymes by p-chloromercuribenzenesulfonate was confirmed with respect to glucose between two Type I isoenzyme preparations purified from the kidney and spleen of rat. Essentially the same difference was observed when galactose was used as the substrate in place of glucose, as the kidney Type I isoenzyme was inhibited in a competitive manner while the spleen counterpart was inhibited in a non-competitive manner by sulfhydryl inhibitor. Both the Type I isoenzymes, however, were competitively inhibited by other mercurial sulfhydryl inhibitors, methyl and butyl mercuric chlorides. On the other hand, the Type II hexokinase isoenzymes purified from the muscle, heart, and spleen were all inhibited competitively by p-chloromercuribenzenesulfonate with respect to glucose. The mechanism of competitive inhibition of the hexokinase isoenzymes by sulfhydryl inhibitors was discussed in view of the difference in the mode of action of the mercurials with different isoenzymes.
对从大鼠肾脏和脾脏中纯化得到的两种I型同工酶制剂而言，对氯汞苯磺酸盐对己糖激酶[EC 2.7.1.1]同工酶的抑制模式在葡萄糖方面存在差异得到了证实。当用半乳糖代替葡萄糖作为底物时，观察到了基本相同的差异，因为肾脏I型同工酶受到巯基抑制剂的竞争性抑制，而脾脏对应同工酶受到非竞争性抑制。然而，两种I型同工酶都受到其他汞基巯基抑制剂（甲基和丁基氯化汞）的竞争性抑制。另一方面，从肌肉、心脏和脾脏中纯化得到的II型己糖激酶同工酶在葡萄糖方面都受到对氯汞苯磺酸盐的竞争性抑制。鉴于汞化合物对不同同工酶的作用模式存在差异，讨论了巯基抑制剂对己糖激酶同工酶的竞争性抑制机制。
