Biochemie und Physiologie: Open Access

Abstrakt

Solution and In silico Ligand Binding Studies of Cicer arietinum Lectin

Madhurima S. Wakankar, Krunal A. Patel, Musti V. Krishnasastry and Sushama M. Gaikwad

The recombinant lectin from Cicer arietinum (rCAL) showed complex sugar specificity and could bind only the asialo triantennary glycan from Fetuin. The thermodynamic study of binding to this glycan indicated the process to be spontaneous and exothermic. The values obtained were, ΔG as -28.56 kJ mol^-1; ΔH as -43.65 kJ mol^-1 and ΔS as -50.65 Jmol^-1K^-1 at 25°C. The presence of four hemopexin-binding domains in the gene sequence indicated possible binding to hemin. Binding of hemin as studied by fluorescence spectroscopy, yielded an association constant of 3.55 x 107 M^-1. The lectin also bound spermine and thiamine with association constants of 1.55 x 104 M^-1 and 5.37 x 103 M^-1, respectively. In silico investigation was carried out by protein-ligand docking using AutoDock Vina software. Binding energies were calculated for each ligand and the amino acids involved in the interaction of these ligands with the rCAL homology model were identified. ASN-8 residue was found to be important in binding of hemin and spermine to rCAL.