Structural studies of opioid peptides: a review of recent progress in x-ray diffraction studies.
The solid state structures of many opioid peptide agonists have been elucidated by x-ray diffraction analysis. Recently, the first structure of an opioid peptide antagonist has been determined. Theoretically, linear peptides can have many different backbone conformations, yet early x-ray studies (1983-1987) on enkephalin and its analogues showed only two different backbone conformations: extended and single beta-bend. In 1989 enkephalin was observed in a third conformation, a double beta-bend. Since that time diffraction studies have been completed on the rationally designed linear opioid peptide agonists DTLET (Tyr-D-Thr-Gly-Phe-Leu-Thr) and DADLE (D-Ala2,D-Leu5-enkephalin) as well as on several cyclic enkephalin analogues including DPDPE (Tyr-[D-Pen-Gly-Phe-D-Pen]) and JOM-13 (Tyr-[D-Cys-Phe-D-Pen]). The most recent review of the x-ray studies on this class of compounds was written in 1988. This paper will update that review to include the results of studies completed since that time.
Laboratory for the Structure of Matter, Naval Research Laboratory, Washington, DC 20375, USA.
J R
JR
Deschamps
C
C
George
J L
JL
Flippen-Anderson
D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D008969:Molecular Sequence Data; D018847:Opioid Peptides / Q000737:chemistry*; D011487:Protein Conformation; D017510:Protein Folding; D014961:X-Ray Diffraction
D018847:Opioid Peptides