Predictions of Protein Circular Dichroism Calculated by the Dipole Interaction Model and Compared to Synchrotron Radiation Circular Dichroism Experiments

Abstract

The determination of accurate secondary, tertiary and quaternary structures of macromolecules is vital for the study of intra- and interbimolecular interactions important for drug discovery, probing enzyme mechanisms and other functional protein complexes. Despite the recent advances in protein structural determination methods like X-ray crystallography, there is still a need to evaluate the accuracy of the model structures used in macromolecular interaction prediction. This is especially important where accurate three dimensional structures of the proteins are absent. Synchrotron radiation circular dichroism (SRCD) is an emerging technique sensitive not only to secondary structure but also teriary and quatertary structure. Theoretical calculations of circular dichroism (CD) using the dipole interaction model have successfully predicted CD for a variety of peptides and monomeric proteins. Herein, the dipole interaction model predicts CD for proteins in monomeric, dimmeric or tetrameric forms and is compared to experimental SRCD spectra. This is an attempt to evaluate the homology models. Preliminary results show comparable CD spectra between the dipole interaction model predictions and SRCD data for small proteins like myoglobin.View Large Image | View Hi-Res Image | Download PowerPoint Slide