By Topic

Laser-induced enzyme reactions in transamination

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
T. Cornish ; University of South Carolina, Charleston, SC, USA ; J. Ledbetter

Ultraviolet laser light produces in pyridoxal-5'-phosphate imines in free solution and in aspartate aminotransferase interesting photochemical reactions. In the amino acid imines in nonaqueous solvents, a proton transfer from the 3-OH group to the imine nitrogen occurs in the excited singlet state. The slow back transfer produces a long-lived transient state which decays with first-order kinetics. Under conditions which do not favor this transfer, as with an ionized 3-0^{\theta} group in the aspartate aminotransferase enzyme, the cofactor crosses over into a triplet state on excitation. This state decays with complicated kinetics. When aspartate aminotransferase binds aspartate, a substrate, a UV-induced band at 500 nm occurs which is not present with α-methylaspartate, an inhibitor. The decay of this band is largely first order with a rate constant of 2600 s-1. This absorption appears to originate from the photoinduced key p -quinoid intermediate structure in the enzyme's mechanism.

Published in:

IEEE Journal of Quantum Electronics  (Volume:20 ,  Issue: 12 )