Acquisition of an Isothermal Titration Calorimetry System

Benedictine University, Lisle

Investigators

Abstract

An isothermal titration calorimetry (ITC) system from MicroCal Incorporated will be used at Benedictine University for biochemical enzymatic studies. The system includes a titration calorimeter and computer for automatic control of the instrument. When two substances interact or combine (noncovalently or covalently), the absorption or evolution of heat occurs. The MicroCal ITC system offers a sensitive and rapid way to determine the amount of heat released or taken up by such a reaction. Computer analysis of the data acquired yields the desired binding or interaction constants. Initially the system will be used in three different projects. Project I involves thestudy of the binding of dihydroxyacetone phosphate (DHAP) analogues to rabbit muscle aldolase (RAMA). This enzyme, which is inexpensive and readily available commercially, catalyzes the addition of DHAP to a variety of aldehydes. As a result, RAMA has been used for the organic synthesis of a number of novel compounds. The analogues will be synthesized and the ability of these compounds to bind to aldolase as a function of their structure will be determined using the ITC system. The information should shed further light on the binding specificity of the aldolase active site and provide further details concerning the enzyme mechanism. Project II will investigate the ability of synthetic crown ethers to bind cesium ions. Cesium-137 is a radioactive byproduct of nuclear reactors. Removal of the cesium from wastewater can be done by extraction with inclusion compounds (e.g., crown ethers). The isothermal titration calorimetry system will be used to rapidly screen the synthetic crown ethers for their ability to bind the cesium ion. The binding of peptides to fibrinogen or the fibrinogen receptors of platelets will be investigated in project III. Peptides will be tested for their ability to bind to fibrinogen or cellular receptors using the isothermal titration calorimetry system. The successful completion of this project will make important contributions to the understanding of the fibrinogen/receptor interaction. Faculty and students will use this instrumentation in interdisciplinary research projects, classroom exercises