title: Photocleavage of avidin by a new pyrenyl probe.
abstract: In this study, a new small-molecule-based reagent was designed to recognize and bind to specific site in protein. A new pyrenyl probe, d-biotinyl-1(1-pyrene)methylamide (Py-biotin) was designed and synthesized by coupling of d-biotin to 1(1-pyrene)methylamine hydrochloride. Binding studies and site-specific photocleavage of avidin by Py-biotin were demonstrated. Binding of Py-biotin to avidin was studied using absorbance and fluorescence spectroscopic techniques. Red shifts of the absorption peak positions of the pyrenyl chromophore followed by hyperchromism were observed upon binding to avidin. The photocleavage of avidin was achieved when a mixture of the protein, Py-biotin, and an electron acceptor, cobalt(III) hexammine trichloride (CoHA), was irradiated at 342nm. No reaction occurred in the absence of the probe, CoHA, or light. N-terminal sequencing of the peptide fragments indicated a cleavage site of avidin between Thr 77 and Val 78. The high specificity of photocleavage may be valuable in targeting specific sites of proteins with small molecules.
authors.affiliation: Department of Chemistry, Faculty of Science, Srinakharinwirot University, Sukhumvit 23, Bangkok 10110, Thailand.
authors.forename: Pinpinat
authors.initials: P
authors.lastname: Malaikaew
authors.forename: Jisnuson
authors.initials: J
authors.lastname: Svasti
authors.forename: Challa V
authors.initials: CV
authors.lastname: Kumar
authors.forename: Apinya
authors.initials: A
authors.lastname: Buranaprapuk
mesh_terms: D000042:Absorption; D001360:Avidin / Q000378:metabolism / Q000528:radiation effects*; D001665:Binding Sites / Q000528:radiation effects; D001710:Biotin / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D002712:Chlorides / Q000378:metabolism; D003035:Cobalt / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D008027:Light; D010446:Peptide Fragments / Q000378:metabolism / Q000528:radiation effects; D010782:Photolysis; D011721:Pyrenes / Q000138:chemical synthesis* / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013912:Threonine / Q000378:metabolism; D014633:Valine / Q000378:metabolism
chemical_list: D002712:Chlorides; D005456:Fluorescent Dyes; D010446:Peptide Fragments; D011721:Pyrenes; C560741:biotinyl-1(1-pyrene)methylamide; C007936:hexaminecobalt (III) trichloride; D001360:Avidin; D013912:Threonine; D003035:Cobalt; D001710:Biotin; C030984:pyrene; D014633:Valine