Implications of Galectin-1 binding to lactose in the dimerization equilibrium

ROMERO, JUAN MANUEL; ESTRIN, DARÍO ARIEL; RABINOVICH, GABRIEL ADRIÁN; DI LELLA, SANTIAGO

Sierra de la Ventana

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Biofísica; 2014

Sociedad Argentina de Biofísica

Galectin-1 is a β-Galatoside binding protein involved in cell communication and differentiation processes.1 It consists of a 134-amino acid domain which has been proved to form a non-covalent homodimer at physiological conditions,2 presumably responsible for the formation of lattices structures on the surface of target cells.3,4 However, little is known about the way these structures are formed and organized. In this work, we employ stopped-flow experiments to measure the rate constants associated with the ligand binding and dimerization processes of recombinant human Galectin-1. From a theoretical perspective, we have studied the ligand unbinding process applying computational simulation techniques.  Interestingly, we find that dimer dissociation process is kinetically affected by the presence of ligand. From a computational perspective, we analyze the molecular determinants of the kinetic barrier to the occupation of water sites as a function of the reaction coordinate. A discussion about the biophysical and biochemical implications of these findings in the formation of the lattices and Galectin-1 function is presented.