Abstract
The binding of β-glycerophosphate (glycerol-2-P) to glycogen phosphorylase b in the crystal has been studied by X-ray diffraction at 3 Å resolution. Glycerol-2-P binds to the allosteric effector site in a position close to that of AMP, glucose-6-P, UDP-Glc, and phosphate. In this position, glycerol-2-P is stabilized through interactions of its phosphate moiety with the guanidinium groups of Arg 309 and Arg 310 which undergo conformational changes, and the hydroxyl group of Tyr 75, while the same residues and solvent are involved in van der Waals interactions with the remaining part of the molecule. Kinetic experiments indicate that glycerol-2-P partially competes with both the activator (AMP) and the inhibitor (glucose 6-phosphate) of phosphorylase b. A comparison of the positions of glycerol-2-P, AMP, glucose 6-phosphate, UDP-Glc, and Pi at the allosteric site is presented.
Original language | English |
---|---|
Pages (from-to) | 62-68 |
Number of pages | 7 |
Journal | Archives of Biochemistry and Biophysics |
Volume | 270 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Jan 1989 |
Funding
We thank Royal Society and British Council for financial support (N.G.O.). We are grateful to Dr. M. S. P. Sansom and Dr. P J. McLaughlin for their help in the initial stages of this work.
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology