Prokai L, Zharikova A D
Center for Drug Discovery, College of Pharmacy, University of Florida, Gainesville 32610-0497, USA.
Rapid Commun Mass Spectrom. 1998;12(22):1796-800. doi: 10.1002/(SICI)1097-0231(19981130)12:22<1796::AID-RCM362>3.0.CO;2-7.
Synaptic metabolism of the endogenous opioid octapeptide dynorphin (Dyn) A (1-8) (Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile) was studied in vitro upon its incubation with synaptosomes and with synaptosomal plasma membranes isolated from rat brain tissue. Electrospray ionization (ESI) and tandem mass spectromety were performed using an ion trap instrument, and afforded the identification of Dyn A (2-8), Dyn A (1-6) and leucine enkephalin [Dyn A (1-5)] as major metabolites. Preliminary quantitative data on the kinetics of Dyn A (1-8) degradation and metabolite formation was obtained by size-exclusion chromatography/ESI tandem mass spectrometry, and revealed an apparent involvement of several enzymes in the metabolism upon incubation with synaptosomes. Predominant formation of Dyn A (1-6) was observed with the synaptosomal plasma membranes.
在体外，将内源性阿片样八肽强啡肽（Dyn）A（1-8）（酪氨酸-甘氨酸-甘氨酸-苯丙氨酸-亮氨酸-精氨酸-精氨酸-异亮氨酸）与突触体以及从大鼠脑组织分离的突触体细胞膜一起孵育，研究其突触代谢。使用离子阱仪器进行电喷雾电离（ESI）和串联质谱分析，鉴定出主要代谢产物为强啡肽A（2-8）、强啡肽A（1-6）和亮氨酸脑啡肽[强啡肽A（1-5）]。通过尺寸排阻色谱/ESI串联质谱获得了强啡肽A（1-8）降解动力学和代谢产物形成的初步定量数据，结果表明，与突触体一起孵育时，几种酶明显参与了代谢过程。在用突触体细胞膜进行孵育时，观察到主要形成强啡肽A（1-6）。
