Unique sequence in deltorphin C confers structural requirement for δ opioid receptor selectivity
作者:LH Lazarus、S Salvadori、P Grieco、WE Wilson、R Tomatis
DOI:10.1016/0223-5234(92)90113-f
日期:1992.11
A series of deltorphin C (H-Tyr-D-Ala-Phe-Asp-Val-Val-Gly-NH2) analogues were synthesized to assess the consequences of changing anionic and hydrophobic residues on delta receptor selectivity. Analogues with altered C-terminal groups, inverted sequences, or esterified with tert-butyl, benzyl, or ethyl groups revealed that high delta selectivity required an unmodified amino acid sequence. Shifts of Asp and hydrophobic residues decreased delta selectivity due to loss in delta affinity (5- to almost-equal-to 700-fold); mu affinity was unchanged or increased 14-fold. Suppression of charge or deamidation diminished delta selectivity through reduced delta and modified mu affinities. Data provide evidence that a negative charge does not a priori guarantee high selectivity and specific alignment of anionic and hydrophobic residues might facilitate optimum spatial configuration which complements the 8 receptor binding site.