Incubation of the myenteric plexus-containing longitudinal muscle layer of guinea pig small intestine with [35S]methionine for up to 9 h resulted in a progressive increase in the incorporation of radioactivity into newly synthesized substance P, neurokinin A and neuropeptide K. The radiolabelled peptides were isolated from tissue extracts by immunoprecipitation using regionally-specific antisera and purified by reverse-phase high performance liquid chromatography. Incorporation of radioactivity into the tachykinins was abolished by cycloheximide and was not observed when [35S]cysteine was substituted for [35S]methionine. The method may be used to study the regulation of biosynthesis and posttranslational modification of protachykinins in the gut.
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience
- Cell Biology