Two-Dimensional Infrared Spectroscopy of Azido-Nicotinamide Adenine Dinucleotide in Water.
National Science Foundation, National Institutes of Health, Bloom's Syndrome Foundation
R01 GM65368,CHE-0644410, R01 GM79368, CHE-0715448,2007256
Department of Chemistry
Mid-IR active analogs of enzyme cofactors have the potential to be important spectroscopic reporters of enzyme active site dynamics. Azido-nicotinamide adenine dinucleotide (NAD+), which has been recently synthesized in our laboratory, is a mid-IR active analog of NAD +, a ubiquitous redox cofactor in biology. In this study, we measure the frequency-frequency time correlation function for the antisymmetric stretching vibration of the azido group of azido-NAD+ in water. Our results are consistent with previous studies of pseudohalides in water. We conclude that azido-NAD+ is sensitive to local environmental fluctuations, which, in water, are dominated by hydrogen-bond dynamics of the water molecules around the probe. Our results demonstrate the potential of azido-NAD+ as a vibrational probe and illustrate the potential of substituted NAD+-analogs as reporters of local structural dynamics that could be used for studies of protein dynamics in NAD-dependent enzymes.
Dutta, S.; Rock, W.; Cook, R. J.; Kohen, A.; and Cheatum, C. M., "Two-Dimensional Infrared Spectroscopy of Azido-Nicotinamide Adenine Dinucleotide in Water." (2011). Faculty and Staff Publications. 95.