Synthesis and properties of human β‐endorphin‐(1–17) and its analogs

Abstract

Four analogs of human β‐endorphin (βh‐EP) were synthesized by the solid‐phase method: βh‐EP‐(1–17) (I), [D‐Ala2]‐βh‐EP‐(1–17) (II), [Gln8]‐βh‐EP‐(1–17) (III) and [D‐Ala2, Gln8]‐βh‐EP‐(1–17) (IV). Measurement in a radio‐receptor binding assay with use of tritiated βh‐EP as primary ligand gave relative potencies as follows: Met‐enkephalin, 100; I, 33; II, 47; III, 889; IV, 123; βh‐endorphin, 2253.