title: A novel 3-step enantioselective synthesis of pyrenylalanine with subsequent incorporation into opioid, CCK, and melanotropin ligands.
abstract: Pyrene possesses unique spectroscopic properties such as a high quantum yield, a long half-life in the excited state, and the ability to form excimers when in proximity to each other in the excited state. These properties allow pyrenylalanine, which is a pyrene moiety incorporated into an amino acid, to be used as a fluorescent probe in peptides and proteins. The common route for the synthesis of pyrenylalanine involves 5 steps, with subsequent separation of the two isomers by recrystallization. This paper reports a novel 3-step asymmetric synthesis of pyrenylalanine with high enantioselectivity, good yields, and facile isomer purification. After synthesis, pyrenylalanine was incorporated into a series of opioid, CCK, and melanotropin peptide ligands in order to study the effects of aromaticity, lipophilicity, and steric properties on their potency and efficacy at their corresponding biological receptors. The change in binding and efficacy of the labeled ligands as compared to the unlabeled ligands demonstrates the possible role of lipophilicity/aromaticity in the binding and signal transduction of the ligand-receptor interaction.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Isabel
authors.initials: I
authors.lastname: Alves
authors.forename: Scott
authors.initials: S
authors.lastname: Cowell
authors.forename: Yeon Sun
authors.initials: YS
authors.lastname: Lee
authors.forename: Xuejun
authors.initials: X
authors.lastname: Tang
authors.forename: Peg
authors.initials: P
authors.lastname: Davis
authors.forename: Frank
authors.initials: F
authors.lastname: Porreca
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Hruby
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism; D000595:Amino Acid Sequence; D002766:Cholecystokinin / Q000031:analogs & derivatives* / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D020881:Enkephalin, D-Penicillamine (2,5)- / Q000031:analogs & derivatives / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D008024:Ligands; D009074:Melanocyte-Stimulating Hormones / Q000737:chemistry* / Q000378:metabolism; D015394:Molecular Structure; D009294:Narcotics / Q000737:chemistry* / Q000378:metabolism; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011721:Pyrenes / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D044101:Receptors, Melanocortin / Q000235:genetics / Q000378:metabolism; D017465:Receptors, Opioid, delta / Q000378:metabolism; D013237:Stereoisomerism
chemical_list: D008024:Ligands; D009294:Narcotics; D009842:Oligopeptides; D011721:Pyrenes; D044101:Receptors, Melanocortin; D017465:Receptors, Opioid, delta; D006160:Guanosine Triphosphate; D020881:Enkephalin, D-Penicillamine (2,5)-; D009074:Melanocyte-Stimulating Hormones; D002766:Cholecystokinin; D000242:Cyclic AMP; D000409:Alanine