ENDOGENOUS INHIBITOR OF ANGIOTENSIN CONVERTING ENZYME IN THE RAT-HEART
ENDOGENOUS INHIBITOR OF ANGIOTENSIN CONVERTING ENZYME IN THE RAT-HEART
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DOI：
10.1016/0006-291x(89)92221-3
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发表时间：
1989-03-31
影响因子：
3.1
通讯作者：
YAMAMOTO, K
中科院分区：
文献类型：
--
作者：
IKEMOTO, F;SONG, GB;YAMAMOTO, K
我们已经在大鼠心脏中发现了一种抑制ACE的物质。该物质被表征为巯基（SH）蛋白，SH部分对于抑制活性是必需的。提取物煮沸后抑制活性消失，超滤液（mol. <10，000），或者当用0.5mM的SH-阻断剂5，5“-二硫代双-（2-硝基甲酸）或ImM的SH氧化剂二酰胺预处理时。该物质经硫丙基琼脂糖亲和层析、40%硫酸铵饱和沉淀和高效液相色谱分离。抑制方式为竞争性抑制。在存在20 μ g/ml该物质的情况下，用5 × 10 - 6 μ g/ml该物质诱导的大鼠主动脉条收缩。10 ~（-8）M ANG I抑制率为60%。这种内源性ACE抑制剂可调节心脏中ACE的活性，以响应组织中氧化还原平衡的改变。
We have identified a substance in the rat heart which inhibits ACE. This substance was characterized to be a sulfhydryl(SH) protein, the SH moiety being essential for the inhibitory activity. The inhibitory activity disappeared when the extract was boiled, or the ultrafiltrate(mol.wt. < 10,000) was used, or when the extract was pretreated with the SH-blocking agent 5,5''-dithiobis-(2-nitro benzoic acid) at 0.5mM or the SH oxidizing agent diamide at 1mM. This substance was fractionated with Thiopropyl Sepharose affinity chromatography, precipitation with 40% ammonium sulfate saturation and high performance liquid chromatography. The mode of inhibition was competitive. In the presence of 20 .mu.g/ml of this substance, the contraction of rat aortic strips induced by 5 .times. 10-8M ANG I was inhibited by 60%. This endogenous inhibitor of ACE may modulate the activity of ACE in the heart, in response to alterations in the oxidation-reduction balance in the tissue.