ENZYMIC DEGRADATION OF LUTEINIZING HORMONE-RELEASING HORMONE (LH-RH) BY HYPOTHALAMIC TISSUE
ENZYMIC DEGRADATION OF LUTEINIZING HORMONE-RELEASING HORMONE (LH-RH) BY HYPOTHALAMIC TISSUE
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DOI：
10.1016/0006-291x(74)90539-7
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发表时间：
1974-01-01
影响因子：
3.1
通讯作者：
FRIDKIN, M
中科院分区：
文献类型：
--
作者：
KOCH, Y;BARAM, T;FRIDKIN, M
人工合成的促黄体生成激素释放激素（LH-RH）在与下丘脑或下丘脑皮质切片或匀浆孵育时失去了其免疫反应性和激素活性。该灭活是由于100，000 × g匀浆上清液部分中存在的可溶性酶降解十肽所致。一只大鼠下丘脑的上清能在5 min内破坏1 μg外源性LH-RH，其主要放射性降解产物为六肽pGlu-His-Trp-Ser-Tyr-Gly，并经连续电泳和纸层析初步证实为Leu-Arg-Pro-Gly-NH_2四肽。这些发现表明Gly-Leu键可能是裂解的优选位点。
Synthetic luteinizing hormone-releasing hormone (LH-RH) lost both its immunore-activity and hormonal activity on incubation with hypothalamic or cerebrocortical slices or homogenates. This inactivation was shown to be due to degradation of the decapeptide by soluble enzyme(s) present in the 100,000 × g supernatant fraction of the homogenates. The supernatant derived from one rat hypothalamus was capable of destroying 1 μg of exogenous LH-RH within 5 min. The hexapeptide pGlu-His-Trp-Ser-Tyr-Gly was identified as the major radioactive breakdown product of [pGlu-3-3H] LH-RH, and tentative evidence for the formation of the tetrapeptide Leu-Arg-Pro-Gly-NH2was obtained by sequential electrophoresis and paper chromatography. These findings suggest that the Gly-Leu bond may be the preferred site of cleavage.