Microcalorimetric studies of interactions between proteins and hydrophobic ligands in hydrophobic interaction chromatography: effects of ligand chain length, density and the amount of bound protein.

摘要: Using isothermal titration calorimetry (ITC), this investigation directly measured the adsorption enthalpies of proteins on various hydrophobic adsorbents. Various amounts butyl and octyl groups were attached onto CM-Sepharose to form C4 C8, two types The both trypsinogen alpha-chymotrypsinogen A at 4.0 M NaCl pH 10.0, in which most ionic interaction was suppressed. isotherms adsorbents also measured, thus allowing us calculate Gibbs free energy entropy adsorption. Experimental results indicated that butyl-containing exothermic, while their ones endothermic. In addition, binding with ligand is basically an process, partition processes. Moreover, or octyl, enthalpy became increasingly positive as density increased, more alkyl chain length adsorbent increased. ITC used measure protein-protein interaction. increased amount bound protein increase appeared be higher than A. This observation implies repulsion stronger among molecules experiments.