title: Differences in heterocycle basicity distinguish homocysteine from cysteine using aldehyde-bearing fluorophores.
abstract: We report the detection of homocysteine over cysteine based upon characteristic differences between 5- and 6-membered heterocyclic amines formed upon reaction with aldehyde-bearing compounds. Homocysteine-derived thiazinane-4-carboxylic acids are more basic than cysteine-derived thiazolidines-4-carboxylic acids. Fluorescence enhancement in response to homocysteine is achieved by tuning pH and excitation wavelength.
authors.affiliation: Department of Chemistry, Portland State University, Portland, Oregon 97207, USA. strongin@pdx.edu.
authors.forename: Aabha
authors.initials: A
authors.lastname: Barve
authors.forename: Mark
authors.initials: M
authors.lastname: Lowry
authors.forename: Jorge O
authors.initials: JO
authors.lastname: Escobedo
authors.forename: Katherine T
authors.initials: KT
authors.lastname: Huynh
authors.forename: Lovemore
authors.initials: L
authors.lastname: Hakuna
authors.forename: Robert M
authors.initials: RM
authors.lastname: Strongin
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000468:Alkalies / Q000737:chemistry*; D003545:Cysteine / Q000032:analysis*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006710:Homocysteine / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence; D053778:Thiazolidines
chemical_list: D000447:Aldehydes; D000468:Alkalies; D005456:Fluorescent Dyes; D053778:Thiazolidines; D006710:Homocysteine; C003438:thiazolidine-4-carboxylic acid; D003545:Cysteine