1. The fluorescent ATP analogue 1,N6-etheno-ATP is a good substrate and an efficient allosteric inhibitor of rabbit skeletal-muscle phosphofructokinase. 2. Fluorescence energy transfer occurs between bound 1,N6-etheno-ATP and phosphofructokinase. 1,N6-Etheno-ATP fluorescence is enhanced, intrinsic protein fluorescence is quenched, and the excitation spectrum of 1,N6-etheno-ATP fluorescence is characteristic of protein absorption. 3. The binding reaction of 1,N6-etheno-ATP observed by stopped-flow fluorimetry is biphasic. The fast phase results from binding to the catalytic site alone. The slow phase results from the allosteric transition of the R conformation into the T conformation induced by the binding of 1,N6-etheno-ATP to the regulatory site. 4. The fluorescence signal that allows the transition of the R conformation into the T conformation to be observed does not arise from 1,N6-etheno-ATP bound to the regulatory site. It arises instead from 1,N6-etheno-ATP bound to the catalytic site as a consequence of changes at the catalytic site caused by the transition of the R conformation into the T conformation. 5. In the presence of excess of Mg2+, the affinity of 1,N6-etheno-ATP for the regulatory site is very much greater in the T state than in the R state.
Skip Nav Destination
Article navigation
November 1979
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
- PDF Icon PDF LinkAdvertising
Research Article|
November 01 1979
The kinetics of effector binding to phosphofructokinase. The allosteric conformational transition induced by 1,N6-ethenoadenosine triphosphate
Publisher: Portland Press Ltd
Online ISSN: 1470-8728
Print ISSN: 0264-6021
© 1979 London: The Biochemical Society
1979
Biochem J (1979) 183 (2): 349–360.
Citation
D Roberts, G L Kellett; The kinetics of effector binding to phosphofructokinase. The allosteric conformational transition induced by 1,N6-ethenoadenosine triphosphate. Biochem J 1 November 1979; 183 (2): 349–360. doi: https://doi.org/10.1042/bj1830349
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.