Nylander I, Tan-No K, Winter A, Silberring J
Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
Life Sci. 1995;57(2):123-9. doi: 10.1016/0024-3205(95)00253-3.
Proteolytic processing of prodynorphin-derived peptides in rat brain was studied with the help of high performance size exclusion chromatography (SEC) connected to electrospray ionization mass spectrometry. Extracts from rat striatum were incubated with individual synthetic dynorphin peptides. Dynorphin A was the most resistant to proteolytic cleavage, converting slowly to Leu-enkephalin (0.3 pmol/min), whereas dynorphin B was processed to this pentapeptide at a 10(4)-fold higher rate. Minor cleavage was also observed between Arg6-Arg7. Alphaneoendorphin was also rapidly metabolized to Leu-enkephalin (6 nmol/min) and, to a lesser extent, to Leu-enkephalinArg6. This new strategy for studying peptidases can easily be adapted to identification of components present in body fluids.
借助与电喷雾电离质谱联用的高效尺寸排阻色谱法（SEC），对大鼠脑中前强啡肽衍生肽的蛋白水解加工过程进行了研究。将大鼠纹状体提取物与单个合成强啡肽肽一起孵育。强啡肽A对蛋白水解切割最具抗性，缓慢转化为亮氨酸脑啡肽（0.3皮摩尔/分钟），而强啡肽B转化为这种五肽的速率要高10⁴倍。在精氨酸⁶-精氨酸⁷之间也观察到少量切割。α新内啡肽也迅速代谢为亮氨酸脑啡肽（6纳摩尔/分钟），并在较小程度上代谢为亮氨酸脑啡肽精氨酸⁶。这种研究肽酶的新策略可以很容易地应用于鉴定体液中存在的成分。
