大鼠下丘脑和垂体亚细胞组分对促黄体生成激素释放激素的降解机制

Mechanism of luteinizing hormone-releasing hormone degradation by subcellular fractions of rat hypothalamus and pituitary.

作者信息

McDermott J R, Smith A I, Biggins J A, Edwardson J A, Griffiths E C

出版信息

Regul Pept. 1982 Mar;3(3-4):257-69. doi: 10.1016/0167-0115(82)90131-8.

Abstract

The pathway of LH-RH degradation by two subcellular fractions (a soluble fraction and a 25 000 X g particulate fraction) of rat hypothalamus, pituitary and cerebral cortex has been studied using high performance liquid chromatography and amino acid analysis to identify the breakdown products. The primary cleavage point in the Tyr5-Gly6 bond giving [1-5] LH-RH and [6-10] LH-RH. In the presence of dithiothreitol, cleavage of LH-RH also occurred at the Pro9-Gly10 bond giving [1-9] LH-RH. The fragment [1-5] LH-RH is further degraded sequentially from the C-terminus and [1-4] LH-RH, [1-3] LH-RH, tyrosine and tryptophan were identified. The other major fragment, [6-10] LH-RH, is rapidly broken down, the only intermediate product positively identified being Arg-Pro.

摘要

利用高效液相色谱法和氨基酸分析来鉴定降解产物，对大鼠下丘脑、垂体和大脑皮层的两个亚细胞组分（可溶性组分和25000×g颗粒组分）中促黄体激素释放激素（LH-RH）的降解途径进行了研究。Tyr5-Gly6键处的主要裂解点产生了[1-5]LH-RH和[6-10]LH-RH。在二硫苏糖醇存在的情况下，LH-RH在Pro9-Gly10键处也发生裂解，产生[1-9]LH-RH。片段[1-5]LH-RH从C端开始进一步依次降解，鉴定出了[1-4]LH-RH、[1-3]LH-RH、酪氨酸和色氨酸。另一个主要片段[6-10]LH-RH迅速分解，唯一确定的中间产物是精氨酸-脯氨酸。