Unique sequence in deltorphin C confers structural requirement for δ opioid receptor selectivity
摘要:
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.
Unique sequence in deltorphin C confers structural requirement for δ opioid receptor selectivity
摘要:
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.
Enzymatic Fragment Condensation of Side Chain-Protected Peptides using Subtilisin A in Anhydrous Organic Solvents: A General Strategy for Industrial Peptide Synthesis
作者:Timo Nuijens、Annette H. M. Schepers、Claudia Cusan、John A. W. Kruijtzer、Dirk T. S. Rijkers、Rob M. J. Liskamp、Peter J. L. M. Quaedflieg
DOI:10.1002/adsc.201200694
日期:2013.1.4
Herein, the enzymaticcondensation of sidechain-protectedpeptidefragmentsusingsubtilisin A in anhydrousorganicsolvents is described. A screening with dipeptide Cbz-Val-Xxx carboxamidomethyl esters with H-Xxx-Val-NH2 nucleophiles was performed, wherein Xxx stands for every (sidechain-protected) amino acid residue. Finally, it was demonstrated that it is feasible to enzymatically condense larger