Investigation of the structural parameters involved in the .mu. and .delta. opioid receptor discrimination of linear enkephalin-related peptides
摘要:
The previous rules proposed for selective recognition of mu and delta opioid receptors by modified enkephalins were investigated through an extensive structure-activity study. Thus, modifications of the sequence of TRIMU 4 (Tyr-D-Ala-Gly-NHCH(CH3)CH2CH(CH3)2, a peptide that exhibits mu selectivity close to that of DAGO (Try-D-Ala-Gly-N(Me)Phe-Gly.ol), were performed for two positions, 2 and 4, critical for mu recognition. The drastic loss of potency following introduction of L-Ala or Aib in position 2 emphasizes the importance of the stereochemistry and the steric size of the X2 amino acid for optimal mu binding. The enhancement of the intrinsic flexibility of the C-terminal alkyl chain of TRIMU 4 through removal of a methyl group leads to TRIMU 5 (Tyr-D-Ala-Gly-NHCH2CH2CH(CH3)2), a peptide with a mu selectivity similar to that of DAGO. In contrast, introduction of an O-tert-butyl Ser2 residue increases affinity for delta receptors. In the hexapeptide series derived from DSLET (Tyr-D-Ser-Gly-Phe-Leu-Thr), a D-Thr2 moiety was shown to be very efficient in improving delta recognition and delta selectivity appeared also to be modulated by the nature of the sixth residue. The potencies of the 24 peptides studied to inhibit the electrically evoked contractions of the GPI or MVD are relatively well correlated with their affinities for brain mu or delta receptors labeled with [3H]DAGO or [3H]DSLET, respectively. Moreover, the analgesic potency (hot plate test) of the peptides is related to their affinity for rat brain mu receptors. The wide range of receptor affinities exhibited by the compounds reported here could be useful to study the physiological role of mu and delta receptors.
The single crystal X-ray diffraction studies of a new tripeptide motif Boc-Tyr-Aib-Xaa-OMe (Xaa = Leu/Ile/Ala) reveal that the peptides adopt β-turn conformations which self-assemble to form a supramolecular double helical structure using various non-covalent interactions in the solid state and the peptides exhibit a type-III N2 sorption isotherm.
A Mechanistic and Kinetic Study of the Formation of Metal Nanoparticles by Using Synthetic Tyrosine-Based Oligopeptides
作者:Satyabrata Si、Rama Ranjan Bhattacharjee、Arindam Banerjee、Tarun K. Mandal
DOI:10.1002/chem.200500834
日期:2006.1.23
of tyrosine residues in the peptide increases. The kinetic study, based on spectrophotometric measurements of the surface plasmon resonance optical property, shows that the rate of formation of gold nanoparticles was much faster at higher pH than at lower pH and was also dependent on the number of tyrosine residues present in the peptide. The dityrosine form of the peptide was found to retain reducing
Novel analogs of enkephalin: identification of functional groups required for biological activity
作者:Fredric A. Gorin、T. M. Balasubramanian、Theodore J. Cicero、John Schwietzer、Garland R. Marshall
DOI:10.1021/jm00184a010
日期:1980.10
Novel tri- and tetrapeptide analogues of enkephalin, in conjunction with earlier structure-activity data, confirm that chemical substitutents present in the first and fourth residues of enkephalin are required for in vitro biological activity. A class of arylamino and alkylamino derivatized tripeptides also were found to have significant in vitro opioid-like activity indistinguishable from [D-Ala2,D-Leu5]enkephalin and morphine.
GACEL, G.;ZAJAC, J. M.;DELAY-GOYET, P.;DAUGE, V.;ROQUES, B. P., J. MED. CHEM., 31,(1988) N 2, 374-383
作者:GACEL, G.、ZAJAC, J. M.、DELAY-GOYET, P.、DAUGE, V.、ROQUES, B. P.
DOI:——
日期:——
Investigation of the structural parameters involved in the .mu. and .delta. opioid receptor discrimination of linear enkephalin-related peptides
作者:G. Gacel、J. M. Zajac、P. Delay-Goyet、V. Dauge、B. P. Roques
DOI:10.1021/jm00397a019
日期:1988.2
The previous rules proposed for selective recognition of mu and delta opioid receptors by modified enkephalins were investigated through an extensive structure-activity study. Thus, modifications of the sequence of TRIMU 4 (Tyr-D-Ala-Gly-NHCH(CH3)CH2CH(CH3)2, a peptide that exhibits mu selectivity close to that of DAGO (Try-D-Ala-Gly-N(Me)Phe-Gly.ol), were performed for two positions, 2 and 4, critical for mu recognition. The drastic loss of potency following introduction of L-Ala or Aib in position 2 emphasizes the importance of the stereochemistry and the steric size of the X2 amino acid for optimal mu binding. The enhancement of the intrinsic flexibility of the C-terminal alkyl chain of TRIMU 4 through removal of a methyl group leads to TRIMU 5 (Tyr-D-Ala-Gly-NHCH2CH2CH(CH3)2), a peptide with a mu selectivity similar to that of DAGO. In contrast, introduction of an O-tert-butyl Ser2 residue increases affinity for delta receptors. In the hexapeptide series derived from DSLET (Tyr-D-Ser-Gly-Phe-Leu-Thr), a D-Thr2 moiety was shown to be very efficient in improving delta recognition and delta selectivity appeared also to be modulated by the nature of the sixth residue. The potencies of the 24 peptides studied to inhibit the electrically evoked contractions of the GPI or MVD are relatively well correlated with their affinities for brain mu or delta receptors labeled with [3H]DAGO or [3H]DSLET, respectively. Moreover, the analgesic potency (hot plate test) of the peptides is related to their affinity for rat brain mu receptors. The wide range of receptor affinities exhibited by the compounds reported here could be useful to study the physiological role of mu and delta receptors.