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本文证明别构抑制剂AMP和dAMP与蛇肌果糖1,6-二磷酸酯酶结合的差光谱,都有270,280和288nm正峰,此外dAMP尚有275nm正峰。计算得到两者结合常数分别为2.0×10~6M~(-1)和1.2×10~6M~(-1)。两者抑制行为不同和AMP的核糖上的2′-羟基与酶的别构部位相互作用有关。胰蛋白酶的限制性酶解引起该酶活力增加,同时受AMP抑制作用丧失,在差光谱上表现为280和288nm负峰,其特征和酶的脲素差光谱一致。说明高活性酶是处于结构松散状态,受AMP抑制的酶则处于紧凑状态,此二种状态均伴随着酪氨酸残基的微环境的改变。
In this paper, the differential spectra of the allosteric inhibitors AMP and dAMP binding to snake muscle fructose 1,6-diphosphatase were found to have positive peaks of 270, 280 and 288 nm. In addition, dAMP has a positive peak of 275 nm. The calculated binding constants are 2.0 × 10 ~ 6M ~ (-1) and 1.2 × 10 ~ 6M ~ (-1) respectively. Both inhibit the different behaviors and AMP 2’-hydroxyl on ribose allosteric site interactions with the enzyme. Restriction enzyme digestion with trypsin resulted in an increase in the activity of this enzyme, accompanied by the loss of AMP inhibition, which showed a negative peak at 280 and 288 nm in the differential spectrum, which was characterized by the same UV spectrum as the enzyme. Indicating that highly active enzymes are in a loosely packed state and enzymes that are inhibited by AMP are in a compact state, both of which are accompanied by changes in the microenvironment of tyrosine residues.