Ruscák M, Orlický J
Physiol Bohemoslov. 1979;28(3):209-16.
Subcellular distribution and some physicochemical properties of alanine aminotransferase in striated muscles of the crayfish, trout, carp, frog, pigeon and rabbit were studied. It was established that: (1) Alanine aminotransferase activity in all mentioned animals occurred almost entirely in the cytosolic fraction of the muscles. Total activity and activity per mg protein were highest in crayfish and pigeon muscles and lowest in carp and trout muscles. (2) The pH optimum for the muscles of homoiotherms and poikilotherms ranged from 7.5 to 8, Km values for L-alanine were of the order 10(-3)--10(-2) M and those for alpha-ketoglutarate 10(-4) M. (3) A 10 degree C temperature increase of the incubation medium was accompanied by a 70--90% increase in activity. (4) The higher the alanine aminotransferase activity of the muscles, the relatively higher their alanine production during electrical stimulation. (5) From the above results it is concluded that alanine aminotransferase in striated muscles regulates the rate of glycolysis and energy production under conditions of anaerobiosis through the formation of alanine.
研究了小龙虾、鳟鱼、鲤鱼、青蛙、鸽子和兔子横纹肌中丙氨酸转氨酶的亚细胞分布及一些理化性质。结果表明：（1）上述所有动物的丙氨酸转氨酶活性几乎全部存在于肌肉的胞质部分。小龙虾和鸽子肌肉中的总活性及每毫克蛋白质的活性最高，而鲤鱼和鳟鱼肌肉中的最低。（2）恒温动物和变温动物肌肉的最适pH值范围为7.5至8，L-丙氨酸的Km值约为10（-3）-10（-2）M，α-酮戊二酸的Km值为10（-4）M。（3）孵育介质温度升高10℃，活性增加70-90%。（4）肌肉中丙氨酸转氨酶活性越高，电刺激期间其丙氨酸生成量相对越高。（5）根据上述结果得出结论，横纹肌中的丙氨酸转氨酶在无氧条件下通过丙氨酸的形成调节糖酵解速率和能量产生。
