amastatin and alpha-neoendorphin

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.

Topics: Animals; Anti-Bacterial Agents; Chromatography, Gel; Corpus Striatum; Dynorphins; Endorphins; Enkephalin, Leucine; Enkephalins; Male; Mass Spectrometry; Peptide Hydrolases; Peptides; Protein Precursors; Rats; Sensitivity and Specificity; Tissue Extracts