Tritiated peptides 12. synthesis and biological activity of tritium labeled 8 phenylalanine substance p
Allen, M.C.; Brundish, D.E.; Wade, R.; Sandberg, B.E.B.; Hanley, M.R.; Iversen, L.L., 1982: Tritiated peptides 12. synthesis and biological activity of tritium labeled 8 phenylalanine substance p. Journal of Medicinal Chemistry 25(10): 1209-1213
Substance P was prepared 3H labeled at Phe8 by catalytic deiodination of a protected precursor. Synthesis of the precursor was by solid-phase methodology on polydimethylacrylamide resin and by condensation in solution of fragments covering sequences 1-4, 5-7 and 8-11. Free peptide made by each route analyzed satisfactorily and had the same chromatographic characteristics as unlabeled substance P. It was indistinguishable from the latter by radioimmunoassay when N and C terminally directed antisera were used and in the ability to cause contractions of isolated guinea pig ileum. Specific radioactivity was 23 Ci/mmol.