Raffin J P
Comp Biochem Physiol B. 1986;85(1):157-62. doi: 10.1016/0305-0491(86)90238-5.
Some regulatory properties of trout gill AMP deaminase were determined in crude extracts, before or after modification of the enzyme by the endogenous proteinase. After proteolysis, the optimal concentrations for activation by sodium and potassium were shifted from 10 to 75 mM, resulting in a large increase of enzyme activity near the physiological potassium concentration. This activation was shown to be the consequence of a much lower sensitivity of AMP deaminase to inhibition by increasing ionic strength. The modified enzyme was also less sensitive to modifications of pH and to inhibition by physiological concentrations of inorganic phosphate. When all these modifications were considered, limited proteolysis of gill AMP deaminase resulted in a 40 times increase of enzyme activity under in vivo conditions.
在粗提取物中，对内源性蛋白酶修饰前后的虹鳟鱼鳃AMP脱氨酶的一些调节特性进行了测定。蛋白水解后，钠和钾激活的最佳浓度从10 mM 变为75 mM，导致在生理钾浓度附近酶活性大幅增加。这种激活被证明是由于AMP脱氨酶对离子强度增加抑制的敏感性大大降低的结果。修饰后的酶对pH值变化和生理浓度无机磷酸盐的抑制也较不敏感。综合考虑所有这些修饰，鳃AMP脱氨酶的有限蛋白水解导致在体内条件下酶活性增加了40倍。
