Biomaterial Database

Conformational determinants of high affinity delta receptor binding of opioid peptides. 1988

C Keys, and P Payne, and P Amsterdam, and L Toll, and G Loew

SRI International, Life Sciences Division, Menlo Park, California 94025.

Detailed conformational analysis of linear and cyclic delta-selective opioid peptides was performed in conjunction with computer-analyzed receptor binding studies with the aim of determining conformational requirements for high affinity binding of peptides to the delta-receptor. The four linear delta-selective hexapeptides included in this study were: DSLET (Tyr-D-Ser-Gly-Phe-Leu-Thr) and its D-Thr2 analog (DTLET) and two t-butyl ether analogs. In one analog an O-t-butyl group replaces the D-Ser2OH and in the other a second O-t-butyl group replaces the D-Thr6OH group as well. This study also includes seven cyclic pentapeptides of the type: Tyr-Cys(Pen-Gly-Phe-Cys(Pen) with various combinations of DL-cysteine and DL-penicillamine (beta-dimethyl cysteine) as the second and fifth residues resulting in varying delta affinities and selectivities. Four (DPLPE, DPDPE, DPLCE, and DCLPE) have both high delta affinity and selectivity; two (DCDCE and DCLCE) have high affinity at both delta- and mu-receptors, and one (LCLCE) has low affinity for both receptors. Our investigation has shown that all analogs that have high affinity at the delta receptor have a unique common low energy conformer. This compact conformer contains intramolecular H-bonds and is very different from the beta II-turn-type structure associated with high affinity mu-receptor binding deduced in our previous work.

UI	MeSH Term	Description	Entries
D008958	Models, Molecular	Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.	Molecular Models,Model, Molecular,Molecular Model
D009294	Narcotics	Agents that induce NARCOSIS. Narcotics include agents that cause somnolence or induced sleep (STUPOR); natural or synthetic derivatives of OPIUM or MORPHINE or any substance that has such effects. They are potent inducers of ANALGESIA and OPIOID-RELATED DISORDERS.	Analgesics, Narcotic,Narcotic Analgesics,Narcotic,Narcotic Effect,Narcotic Effects,Effect, Narcotic,Effects, Narcotic
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D010456	Peptides, Cyclic	Peptides whose amino acid residues are linked together forming a circular chain. Some of them are ANTI-INFECTIVE AGENTS; some are biosynthesized non-ribosomally (PEPTIDE BIOSYNTHESIS, NON-RIBOSOMAL).	Circular Peptide,Cyclic Peptide,Cyclic Peptides,Cyclopeptide,Orbitide,Circular Peptides,Cyclopeptides,Orbitides,Peptide, Circular,Peptide, Cyclic,Peptides, Circular
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D011957	Receptors, Opioid	Cell membrane proteins that bind opioids and trigger intracellular changes which influence the behavior of cells. The endogenous ligands for opioid receptors in mammals include three families of peptides, the enkephalins, endorphins, and dynorphins. The receptor classes include mu, delta, and kappa receptors. Sigma receptors bind several psychoactive substances, including certain opioids, but their endogenous ligands are not known.	Endorphin Receptors,Enkephalin Receptors,Narcotic Receptors,Opioid Receptors,Receptors, Endorphin,Receptors, Enkephalin,Receptors, Narcotic,Receptors, Opiate,Endorphin Receptor,Enkephalin Receptor,Normorphine Receptors,Opiate Receptor,Opiate Receptors,Opioid Receptor,Receptors, Normorphine,Receptors, beta-Endorphin,beta-Endorphin Receptor,Receptor, Endorphin,Receptor, Enkephalin,Receptor, Opiate,Receptor, Opioid,Receptor, beta-Endorphin,Receptors, beta Endorphin,beta Endorphin Receptor,beta-Endorphin Receptors
D003196	Computer Graphics	The process of pictorial communication, between human and computers, in which the computer input and output have the form of charts, drawings, or other appropriate pictorial representation.	Computer Graphic,Graphic, Computer,Graphics, Computer
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships
D013816	Thermodynamics	A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)	Thermodynamic
D017465	Receptors, Opioid, delta	A class of opioid receptors recognized by its pharmacological profile. Delta opioid receptors bind endorphins and enkephalins with approximately equal affinity and have less affinity for dynorphins.	Opioid Receptors, delta,Receptors, delta,Receptors, delta Opioid,delta Receptors,delta Opioid Receptor,delta Receptor,Opioid Receptor, delta,Receptor, delta,Receptor, delta Opioid,delta Opioid Receptors