Binding and Kinetic Studies of Liver Alcohol Dehydrogenase-Coenzyme-Pyrazole Complexes
Year: 1970
Type: article
Abstract: Complexes of liver alcohol dehydrogenase with pyrazole and NAD+, NHD+, or AcPyAD+ were studied by spectral, kinetic, and equilibrium binding techniques. Difference spectra showed the same peak, 290 mµ, for ternary complex with NAD+ or NHD+ as coenzyme but with AcPyAD+ as coenzyme the peak appeared at 308 mµ. The dissociation constants of coenzyme from the ternary complex were much higher for the two analogues than for NAD+. Stopped flow studies showed that for NHD+ the higher dissociation constant was due to a decreased on velocity of the coenzyme but for AcPyAD+ it was due to a higher off velocity than NAD+. The dissociation constants of pyrazole from the ternary complexes were the same for complexes with NAD+ and NHD+ but 8-fold higher for complex containing AcPyAD+. This was due to a much slower pyrazole on velocity. The results of this study indicate that pyrazole interacts with the nicotinamide ring of NAD+ in the ternary complex. The nature of this interaction is discussed.
Source: Journal of Biological Chemistry
Authors: Joseph D. Shore, Martha J. Gilleland
Institution: Henry Ford Hospital
Language: English
Topic: Chemical Reaction Mechanisms
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W1552270283