title: Detection of peptidyl-3,4-dihydroxyphenylalanine by amino acid analysis and microsequencing techniques.
abstract: 3,4-Dihydroxyphenylalanine (DOPA) is an amino acid that occurs naturally in the primary sequence of many proteins and peptides. Detection of peptidyl-DOPA, however, can be elusive. This is due (i) to its coelution with leucine on most of the ion exchangers used in amino acid analysis and (ii) to the coelution of phenylthiohydantoin (PTH)-DOPA with PTH-alanine during routine C18 reversed-phase HPLC following automated Edman degradation. By application of appropriately timed temperature and/or gradient modifications during chromatography, DOPA and its PTH derivative can be adequately resolved for detection by both amino acid analysis and gas-phase sequencing.
authors.affiliation: Marine Biology/Biochemistry Program, College of Marine Studies, University of Delaware, Lewes 19958.
authors.forename: J H
authors.initials: JH
authors.lastname: Waite
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives* / Q000032:analysis*; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis*; D010669:Phenylthiohydantoin / Q000031:analogs & derivatives / Q000032:analysis; D013696:Temperature
chemical_list: D000596:Amino Acids; D010455:Peptides; C068906:phenylthiohydantoin-3,4-dihydroxyphenylalanine; D010669:Phenylthiohydantoin; D004295:Dihydroxyphenylalanine