Logo image
3-Picolyl Azide Adenine Dinucleotide as a Probe of Femtosecond to Picosecond Enzyme Dynamics
Journal article   Peer reviewed

3-Picolyl Azide Adenine Dinucleotide as a Probe of Femtosecond to Picosecond Enzyme Dynamics

Samrat Dutta, Yun-Liang Li, William Rock, Jon C. D Houtman, Amnon Kohen and Christopher M Cheatum
The journal of physical chemistry. B, Vol.116(1), pp.542-548
01/12/2012
DOI: 10.1021/jp208677u
PMCID: PMC3260785
PMID: 22126535

View Online

Abstract

Functionally relevant femtosecond to picosecond dynamics in enzyme active sites can be difficult to measure because of a lack of spectroscopic probes that can be located in the active site without altering the behavior of the enzyme. We have developed a new NAD+ analog 3-Picolyl Azide Adenine Dinucleotide (PAAD+), which has the potential to be a general spectroscopic probe for NAD-dependent enzymes. This analog is stable and binds in the active site of a typical NAD-dependent enzyme formate dehydrogenase (FDH) with characteristics similar to those of natural NAD+. It has an isolated infrared transition with high molar absorptivity that makes it suitable for observing enzyme dynamics using 2D IR spectroscopy. 2D IR experiments show that in aqueous solution, the analog undergoes complete spectral diffusion within hundreds of femtoseconds consistent with the water hydrogen bonding dynamics that would be expected. When bound to FDH in a binary complex, it shows picosecond fluctuations and a large static offset, consistent with previous studies of the binary complexes of this enzyme. These results show that PAAD+ is an excellent probe of local dynamics and that it should be a general tool for probing the dynamics of a wide range of NAD-dependent enzymes.
B: Biophysical Chemistry

Details

Metrics

Logo image