title: Characterization of cyclic peptides containing disulfide bonds.
abstract: Unlike linear peptides, analysis of cyclic peptides containing disulfide bonds is not straightforward and demands indirect methods to achieve a rigorous proof of structure. Three peptides that belong to this category, p-Cl-Phe-DPDPE, DPDPE, and CTOP, were analyzed and the results are presented in this paper. The great potential of two dimensional NMR and ESI tandem mass spectrometry was harnessed during the course of peptide characterizations. A new RP-HPLC method for the analysis of trifluoroacetic acid is also presented. It is robust, simple, and efficient compared to the currently available methods.
authors.affiliation: Pharmaceutical Development Section, Biosciences Division, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025 United States of America.
authors.forename: Mindy
authors.initials: M
authors.lastname: Johnson
authors.affiliation: Pharmaceutical Development Section, Biosciences Division, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025 United States of America.
authors.forename: Mingtao
authors.initials: M
authors.lastname: Liu
authors.affiliation: Pharmaceutical Development Section, Biosciences Division, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025 United States of America.
authors.forename: Elaine
authors.initials: E
authors.lastname: Struble
authors.affiliation: Pharmaceutical Development Section, Biosciences Division, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025 United States of America. Electronic address: kanthi.hettiarachchi@gmail.com.
authors.forename: Kanthi
authors.initials: K
authors.lastname: Hettiarachchi
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004220:Disulfides / Q000737:chemistry*; D004229:Dithiothreitol / Q000737:chemistry; D020881:Enkephalin, D-Penicillamine (2,5)- / Q000737:chemistry; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D010456:Peptides, Cyclic / Q000737:chemistry*; D013004:Somatostatin / Q000031:analogs & derivatives / Q000737:chemistry; D053719:Tandem Mass Spectrometry; D014269:Trifluoroacetic Acid
chemical_list: D004220:Disulfides; D007202:Indicators and Reagents; D010456:Peptides, Cyclic; C049352:phenylalanyl-cyclo(cysteinyltyrosyl-tryptophyl-ornithyl-threonyl-penicillamine)threoninamide; D013004:Somatostatin; D020881:Enkephalin, D-Penicillamine (2,5)-; D014269:Trifluoroacetic Acid; D019342:Acetic Acid; D004229:Dithiothreitol
keywords: Opioid peptides; RP-HPLC; Tandem mass spectrometry; Trifluoroacetic acid; Two-dimensional NMR