Studies on High Molecular Weight Renin from Hog Kidney
Studies on High Molecular Weight Renin from Hog Kidney
复制标题
猪肾高分子量肾素的研究
作者：
M. Levine;K. Lentz;J. R. Kahn;F. Dorer
先前几位研究者关于高分子量肾素活化的报道尚未得到证实。改进了用甲苯提取猪肾的简单方法，仅得到分子量为60，000的部分纯化的肾素。试图通过酸化来增加这种肾素的活性导致总活性的20-90%的损失，尽管剩余的肾素活性被转化为40，000的分子量，并且其比活性比原始的增加了10倍。通过在酸化之前加入粗肾提取物来提高60，000分子量的肾素活性的尝试没有导致活化。活性的肾素部分纯化的程序，涉及酸化抑制粗肾提取物的加入。单独孵育增加量的粗肾提取物导致产生的angfotensin进行性减少。当血管紧张素曲线外推到提取物浓度为零时，肾素活性水平是酸化这种粗提物后发现的水平的两倍。高血管紧张素酶活性的粗提取物被EDTA部分抑制，但在后者的存在下，二异丙基氟磷酸和苯甲磺酰氟，单独或一起，没有得到额外的保护。此类提取物中高分子量凝乳酶的重要性尚不清楚，尽管很明显，正如一些研究人员所建议的那样，它不是凝乳酶活性较低的前体。
Previous reports by several investigators on the activation of a high molecular weight renin have not been confirmed. A simple method of extracting hog kidneys by using toluene was modified to yield partially purified renin with a molecular weight of 60,000, exclusively. Attempts to increase the activity of this renin by acidification resulted in a loss of 20-90% of the total activity, although the renin activity remaining was converted to a molecular weight of 40,000 and its specific activity increased 10-fold over that of the original. Attempts to obtain increased activity of the 60,000 molecular weight renin by adding crude kidney extract before the acidification did not result in activation. Activity of renin partially purified by a procedure involving acidification was inhibited by the addition of crude kidney extract. Incubation of increasing amounts of crude kidney extract alone resulted in a progressive reduction in angfotensin produced. When the angiotensin curve was extrapolated to zero extract concentration, (be level of renin activity was twice as great as that found after acidification of such crude extracts. The high angiotensinase activity of the crude extract was partially inhibited by EDTA, but in the presence of the latter, diisopropylfluoropbosphate and phenylmethanesulfonyl fluoride, alone or together, gave no added protection. The significance of the high molecular weight renin in such extracts is not clear, although it is apparent that it is not a less active precursor of renin, as has been suggested by some investigators.