The use of computers in the teaching of hormone receptor interactions in the presence of two types of binding sites or negative cooperativity

SANTA COLOMA TA,; CALVO JC.

BIOCHEMICAL EDUCATION

Instituto de Biologia y Medicina Experimental

Año: 1988 vol. 16 p. 90 - 91

0307-4412

A unique aspect of biological systems is that manyimportant molecular species are high molecular weightpolymers. These macromolecules participate in everyaspect of cellular activity. Indeed, interactions betweenthese macromolecules and small molecules define the veryprocesses of life.The binding of hormones to their receptors are thesubject of intense research interest. One approach to theinvestigation of these interactions has been to study thebinding of radioactivity labeled hormone analogs toreceptor sites. When the binding of ligands to macromoleculesobeys the law of mass action, the analysis ofequilibrium binding data is simple. Among the manyavailable methods of graphical analysis, the most popularis the one described by Berson and Yalow, 1 derived fromthe Scatchard interpretation of binding data. 2 However,when studying binding of ligand to macromolecules, theexistence of site-site interactions complicates anystraightforward interpretation of the binding parameters.Frequently, the binding of a small molecule to one siteaffects the binding of another small molecule to anothersite. Interactions between sites considerably augment thecomplexity of the problem and increase the difficulty ofthe analytical solution.This report is a description of a computer programdesigned to teach the graphical aspect of the analysis ofligand-receptor interaction, considering two binding sitesper receptor molecule.