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.
Deschamps
J R
JR
Laboratory for the Structure of Matter, Naval Research Laboratory, Washington, DC 20375, USA.
George
C
C
Flippen-Anderson
J L
JL
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