title: Photoswitchable multivalent sugar ligands: synthesis, isomerization, and lectin binding studies of azobenzene-glycopyranoside derivatives.
abstract: Coating of azobenzene chromophore with multivalent sugar ligands has been accomplished. Such sugar coating allows the study of the isomerization properties of this chromophore in aqueous solutions. The predominantly cis-isomer-containing photostationary state (PS) mixture of these azobenzene derivatives is found to be stable for hours. The rate constants for their isomerization, as well as the Arrhenius activation energies, are determined experimentally. An assessment of the lectin binding properties of the lactoside bearing isomeric azobenzene derivatives, by isothermal calorimetric methods, reveals the existence of an unusual cooperativity in their binding to lectin peanut agglutinin. Thermodynamic parameters evaluated for the trans and the PS mixture are discussed, in detail, for the lactoside bearing bivalent azobenzene derivative.
authors.affiliation: Department of Organic Chemistry and Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India.
authors.forename: Oruganti
authors.initials: O
authors.lastname: Srinivas
authors.forename: Nivedita
authors.initials: N
authors.lastname: Mitra
authors.forename: Avadhesha
authors.initials: A
authors.lastname: Surolia
authors.forename: Narayanaswamy
authors.initials: N
authors.lastname: Jayaraman
mesh_terms: D001391:Azo Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D006027:Glycosides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D007536:Isomerism; D007700:Kinetics; D008024:Ligands; D019887:Peanut Agglutinin / Q000737:chemistry* / Q000378:metabolism; D010777:Photochemistry; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
chemical_list: D001391:Azo Compounds; D006027:Glycosides; D008024:Ligands; D019887:Peanut Agglutinin; C009850:azobenzene