Understanding the dynamics of the cyclophilins family of enzymes and their interactions with their CD147 receptor.
EMSL Project ID
30425
Abstract
Enzyme motions associated with catalysis have been found to occur even in the absence of substrates and localize to similar regions. This inherent flexibility may allow important conformations to be dynamically sampled, such as those that initiate substrate binding, suggesting that enzyme dynamics are critical for function. However, it is unknown whether inherent motions are unique to these particular members or are conserved across enzyme families and how these motions are related to sequence, structure, and function. Thus, the long-term goal of this proposed study is to determine how inherent motions compare within an enzyme family and to begin determining the relationship between sequence, structure, dynamics, and function. Such knowledge would be instrumental in understanding the evolutionary pressures that dictate protein motions in addition to those that dictate catalysis. Moreover, structure has aided the development of approaches for the rational design of therapeutics and understanding the dynamics of such moving targets may further advance such strategies.NMR solution studies will be used to probe enzyme motions at atomic resolution. The novelty in this approach is that active enzyme complexes can be monitored because of the nature of the reversible reaction in which they catalyze. This provides an important link between dynamics and function, since how inherently dynamic regions of enzymes are preempted for catalysis can be directly probed, as opposed to inferred from static structures. By combining these methods with mutagenesis, local contributions to the global dynamics within a particular enzyme can be measured and by studying several enzymes within a particular family, the dynamic contributions of both conserved and non-conserved residues can be determined.
Cyclophilins catalyze the reversible cis/trans interconversion of peptidyl-prolyl bonds and are both overexpressed in multiple cancers and utilized by several viruses for infection, including Human Immunodeficiency virus type-1 (HIV-1). Motions within the prototypical family member, cyclophilin-A (CypA), have recently been detected in the absence of substrate yet are similar to its rate of catalytic turnover. Here, inherent motions will be characterized for multiple cyclophilin members both in the absence and presence of their endogenous receptor substrate, CD147. These investigations will help determine how motions have been conserved and how amino acid differences may regulated dynamics as they are related to catalytic function.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2008-10-01
End Date
2011-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Redzic JS, GS Armstrong, NG Isern, DN Jones, JS Kieft, and EZ Eisenmesser. 2011. "The retinal specific CD147 Ig0 domain: from molecular structure to biological activity." Journal of Molecular Biology 411(1):68-82. doi:10.1016/j.jmb.2011.04.060
Schlegel J, GS Armstrong, JS Redzic, F Zhang, and EZ Eisenmesser. 2009. "Characterizing and controlling the inherent dynamics of cyclophilin-A." Protein Science 18(4):811-824. doi:10.1002/pro.89
Schlegel J, JS Redzic, C Porter, V Yurchenko, M Bukrinsky, W Labeikovsky, GS Armstrong, F Zhang, NG Isern, J Degregori, R Hodges, and EZ Eisenmesser. 2009. "Solution characterization of the extracellular region of CD147 and its interaction with its enzyme ligand cyclophilin-A." Journal of Molecular Biology 391(3):518-535. doi:10.1016/j.jmb.2009.05.080