Protein-mediated efficient synergistic "antenna effect" in a ternary system in D₂O medium.
A ternary system consisting of a protein, catechin (either + or - epimer), and Tb(III) in suitable aqueous buffer medium at physiological pH (= 6.8) has been shown to exhibit highly efficient "antenna effect". Steady state and time-resolved emission studies of each component in the binary complexes (protein with Tb(III) and (+)- or (-)-catechin with Tb(III)) and the ternary systems along with the molecular docking studies reveal that the efficient sensitization could be ascribed to the effective shielding of microenvironment of Tb(III) from O-H oscillator and increased Tb-C (+/-) interaction in the ternary systems in aqueous medium. The ternary system exhibits protein-mediated efficient antenna effect in D(2)O medium due to synergistic ET from both the lowest ππ* triplet state of Trp residue in protein and that of catechin apart from protection of the Tb(III) environment from matrix vibration. The simple system consisting of (+)- or (-)-catechin and Tb(III) in D(2)O buffer at pH 6.8 has been prescribed to be a useful biosensor.
Department of Chemistry and Biochemistry, Presidency University, Kolkata 700073, India.
Shyamal Kr
SK
Ghorai
Swarna Kamal
SK
Samanta
Manini
M
Mukherjee
Sanjib
S
Ghosh
D000818:Animals; D015374:Biosensing Techniques; D002021:Buffers; D002392:Catechin / Q000737:chemistry*; D002417:Cattle; D003198:Computer Simulation; D017666:Deuterium Oxide / Q000737:chemistry*; D004735:Energy Transfer; D006801:Humans; D006863:Hydrogen-Ion Concentration; D049449:Luminescence; D008163:Luminescent Measurements; D008958:Models, Molecular; D012709:Serum Albumin / Q000032:analysis*; D012710:Serum Albumin, Bovine / Q000032:analysis*; D013237:Stereoisomerism; D013725:Terbium / Q000737:chemistry*; D013816:Thermodynamics; D014867:Water
D002021:Buffers; D012709:Serum Albumin; D014867:Water; D013725:Terbium; D012710:Serum Albumin, Bovine; D002392:Catechin; D017666:Deuterium Oxide