title: Opioid receptor binding and antinociceptive activity of the analogues of endomorphin-2 and morphiceptin with phenylalanine mimics in the position 3 or 4.
abstract: Endomorphin-2 (EM-2) and morphiceptin are the same class of putative mu-opioid receptor ligands. To investigate the effectiveness of phenylglycine (Phg, L or D) and homophenylalanine (Hfe) as the surrogates of phenylalanine in the position 3 and/or 4 of them, a series of their analogues were synthesized. Opioid receptor binding affinities were determined. Two analogues, [Hfe3]EM-2 and [Phg4] (EM-2/morphiceptin), showed different but potent antinociceptive activity in mouse hot-plate test, the results combined with their half-lives of degradation by mouse brain homogenate could also present some evidence to the in vivo degradative mechanism of EM-2.
authors: Department of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors: Yanfeng
authors: Y
authors: Gao
authors: Xin
authors: X
authors: Liu
authors: Weixia
authors: W
authors: Liu
authors: Yuanming
authors: Y
authors: Qi
authors: Xuefeng
authors: X
authors: Liu
authors: Yifeng
authors: Y
authors: Zhou
authors: Rui
authors: R
authors: Wang