The Contribution of Fast Protein Dynamics to Cytochrome P450 Molecular Recognition Characterized by Two-Dimensional Infrared Spectroscopy

Abstract

While there is much interest in the potential contribution of fast protein dynamics to biological function, it remains a hotly debated topic in large part due to the challenges associated with experimentally characterizing fast protein motions. However, recent advances in the technique of two-dimensional infrared (2D-IR) spectroscopy now enable the study of fast protein fluctuations. One biological function where fast dynamics may play a particularly important role is molecular recognition. Molecular recognition of cytochrome (cyt) P450s is recognized as being particularly important to human health. Cyt P450s are a large family of enzymes that catalyze the hydroxylation of a wide variety of substrates and show varying degrees of substrate specificity. While dynamics have been implicated in the substrate specificity of cyt P450s, previous experimental studies have lacked sufficient time resolution. Thus, to overcome this limitation we are applying 2D-IR spectroscopic techniques toward the characterizing the role of dynamics in the substrate specificity of cyt P450 enzymes. Initial studies have focused on how the binding of different substrates affects the active site dynamics of the paradigmatic, relatively substrate-specific cyt P450cam. These and further studies of more substrate-promiscuous members of the cyt P450 family will assess the contribution of dynamics to molecular recognition, and provide a model for the contribution of fast protein motions to other biological systems.