Kertscher U, Brudel M, Mehlis B, Sandow J, Berger H
Department of Peptide Pharmacology, Research Institute of Molecular Pharmacology, Berlin, F.R.G.
J Pharmacol Exp Ther. 1995 May;273(2):709-15.
The pathways of in vitro degradation of the gonadotropin-releasing hormone (GnRH) analog buserelin [pGlu-His-Trp-Ser-Tyr-D-Ser(tBu)-Leu-Arg- ProNHEt, B1-9] by the rat kidney membrane fraction was investigated using high-performance liquid chromatography for the separation of the peptide products and electrospray mass spectrometry for their identification. The N-terminal peptides B1-4, B1-3, B1-2, C-terminal peptides B3-9, B4-9, B5-9, B6-9, middle sequence B3-4 and the amino acids Trp, Ser and Tyr were found to be formed. However, due to extreme differences in the stability of the peptides toward the battery of membrane enzymes (B1-2, B6-9 >> B1-3, B5-9 >> B1-9 >> B1-4 > B4-9 > B3-9, B3-4), the final products of buserelin degradation were B1-2, B1-3, B5-9, and B6-9 and the amino acids Ser and, corresponding to the formation of B1-2 and B6-9, Trp and Tyr, respectively. The sequences B3-9, B4-9 and B3-4 were clearly detectable only when the inhibitors of aminopeptidases amastatin and bestatin were included in the incubations.(ABSTRACT TRUNCATED AT 250 WORDS)
利用高效液相色谱法分离肽产物，并通过电喷雾质谱法进行鉴定，研究了促性腺激素释放激素（GnRH）类似物布舍瑞林[pGlu-His-Trp-Ser-Tyr-D-Ser(tBu)-Leu-Arg-ProNHEt，B1-9]在大鼠肾膜组分中的体外降解途径。发现形成了N端肽B1-4、B1-3、B1-2、C端肽B3-9、B4-9、B5-9、B6-9、中间序列B3-4以及氨基酸色氨酸、丝氨酸和酪氨酸。然而，由于这些肽对一系列膜酶的稳定性存在极大差异（B1-2、B6-9 >> B1-3、B5-9 >> B1-9 >> B1-4 > B4-9 > B3-9、B3-4），布舍瑞林降解的最终产物是B1-2、B1-3、B5-9和B6-9以及氨基酸丝氨酸，对应于B1-2和B6-9的形成，分别还有色氨酸和酪氨酸。只有当孵育中加入氨肽酶抑制剂抑氨肽酶和贝司他汀时，序列B3-9、B4-9和B3-4才能被清晰检测到。（摘要截短于250字）
