title: Nanosecond generation of tyrosyl radicals via laser-initiated decaging of oxalate-modified amino acids.
abstract: We describe a general method for the unimolecular photochemical generation of tyrosyl radicals from a diaryl oxalate ester platform on the nanosecond time scale. Symmetric and asymmetric tyrosine oxalate esters have been prepared in gram quantities. Direct photocleavage of the oxalate linkage by laser flash photolysis affords tyrosyl radicals within 50 ns. This approach provides unnatural caged amino acids that may be incorporated into model and biological systems for the study of proton-coupled electron transfer in enzymatic catalysis.
authors.affiliation: Department of Chemistry, 6-335, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, USA.
authors.forename: Michelle C Y
authors.initials: MC
authors.lastname: Chang
authors.forename: Scott E
authors.initials: SE
authors.lastname: Miller
authors.forename: Scott D
authors.initials: SD
authors.lastname: Carpenter
authors.forename: JoAnne
authors.initials: J
authors.lastname: Stubbe
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Nocera
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D004579:Electron Transport; D004952:Esters / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry; D007834:Lasers; D008956:Models, Chemical; D015394:Molecular Structure; D010070:Oxalates / Q000737:chemistry*; D010777:Photochemistry / Q000379:methods*; D010782:Photolysis; D013997:Time Factors; D014443:Tyrosine / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D004952:Esters; D005609:Free Radicals; D010070:Oxalates; D014443:Tyrosine