SYNTHESIS AND OPIOID ACTIVITY OF TYROSINE SULFATE-CONTAINING DERMORPHIN AND DELTORPHIN PEPTIDES

To study the effect of the sulfate ester moiety on the opioid activity , we prepared two tyrosine sulfate-(Tyr(SO3H))-containing dermorphin a nd deltorphin peptides. Their activities weve determined in binding st udies based on displacement of mu- and delta-receptor selective radiol abels from rat brain membranes and in two bioassays, using guinea pig ileum and mouse vas deferens. In comparison to original peptides and m orphine, the obtained data indicate that whereas H-Tyr(SO3H)-D-Ala-Phe -Gly-NH2 shows very minimal interaction with opioid receptors, H-Tyr(S O3H)-D-Ala-Phe-Asp-Val-Val-Gly-NH2 retains a significant activity.