Comparison of crude bovine subcortical substance P with synthetic substance P

Summary Synthetic substance P (SP) was compared with the gut-contracting peptide Fa from bovine subcortex by means of thin-layer chromatography, paper electrophoresis, enzymatic digestion, and biological assays. With all four techniques differences in behaviour between Fa and synthetic SP were found, which lead to the conclusion that both active principles are similar but not identical. Both materials could also be distinguished from synthetic physalaemin with the aid of paper electrophoresis and thin-layer chromatography.