Interaction of colchicine with human serum albumin investigated by spectroscopic methods

We investigated the interaction between colchicine and human serum albumin (HSA) by fluorescence and UV-vis absorption spectroscopy. In the mechanism discussion, it was proved that the fluorescence quenching of HSA by colchicine is a result of the formation of colchicines-HSA complex; van der Waals interactions and hydrogen bonds play a major role in stabilizing the complex. The modified Stern-Volmer quenching constant K-a and corresponding thermodynamic parameters Delta H, Delta G, Delta S at different temperatures were calculated. The distance r between donor (Trp(214)) and acceptor (colchicine) was obtained according to fluorescence resonance energy transfer (FRET). (c) 2005 Elsevier B.V. All rights reserved.