Affiliation:
1. Department of Chemistry University of Calcutta 92, A. P. C. Road Kolkata 700009 West Bengal
2. Jadavpur University Department of Chemistry Kolkata West Bengal -700032 India.
3. Narendrapur Ramkrishna Mission Department of Chemistry Kolkata West Bengal 700103 India
4. Department of Chemistry School of Sciences Cluster University of Jammu, Canal Road Jammu -180001 India.
Abstract
AbstractSometimes unusual redox chemistry and modulation of enzyme activity Cu‐proteins can be encountered by the presence of a trace amount of Cu−Tris interaction (Tris‐(hydroxymethyl) aminomethane) during vitro studies. Herein, we addressed a redox chemistry of CuII−Tris with variable stoichiometric ratios in the presence of ascorbic acid (H2A) and O2. The redox chemistry of Bs3 (Cu : Tris; 1 : 3) with H2A/O2 was passed through several intermediates with progress on time yielding initially yellow precipitate, (Yp3), then green solution, (Gs3) and finally cyan solution (Cs3). The UV‐Vis spectra of Bs3, Gs3 and Cs3 displayed peaks at 640, 690 and 710 nm respectively suggesting CuII. The redox potential of CuII/CuI in Bs3, Gs3 and Cs3 were −0.18 V, −0.15 V and −0.19 V (vs. Ag/AgCl) respectively. The EPR spectrum of Bs3 showed an axial signal with g∥,⊥=2.483/2.105&A∥=160×10−4 cm−1 whereas Gs3 and Cs3 showed rhombic signal with g1,2,3=2.302/2.063/2.018&A∥=177×10−4 cm−1 and g1,2,3=2.274/2.064/2.016&A∥=164×10−4 cm−1 respectively suggesting a distorted tetragonal geometry. ESI−MS data indicated the probable composition of Bs2‐Bs5, Gs3 and Cs3 in solution. Integration of all spectroscopies data demonstrated the probable composition and redox mechanism.
Funder
University Grants Commission of Bangladesh
Department of Chemistry, University of York
Centre de Regulació Genòmica