• 1 January 1982
    • journal article
    • research article
    • Vol. 20  (3) , 199-206
Abstract
The Gly3 residue in Gly2- and D-Ala2-enkephalins was replaced by .DELTA. Ala3 and Ser3 in order to examine the effect on binding to the .delta. and .mu. opiate receptors. [D-Ala2,.DELTA. Ala3, Leu5]-enkephalin maintains most of its receptor binding affinities for both sites. Apparently, the proper conjunctions of positions 2 and 3 of the enkephalin sequence are important to receptor preference and position 3 may have a very specific interaction with the .delta. receptor. The in vivo analgesic and CNS activities of the peptides are also discussed.