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Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Inhibition Of Fructose-1,6-Bisphosphatase By A New Class Of Allosteric Effectors, Jun-Young Choe, Scott W. Nelson, Kristen L. Arienti, Frank U. Axe, Tassie L. Collins, Todd K. Jones, Rachel D.A. Kimmich, Michael J. Newman, Karl Norvell, William C. Ripka, Suzanne J. Romano, Kevin M. Short, Deborah H. Slee, Herbert J. Fromm, Richard B. Honzatko Dec 2003

Inhibition Of Fructose-1,6-Bisphosphatase By A New Class Of Allosteric Effectors, Jun-Young Choe, Scott W. Nelson, Kristen L. Arienti, Frank U. Axe, Tassie L. Collins, Todd K. Jones, Rachel D.A. Kimmich, Michael J. Newman, Karl Norvell, William C. Ripka, Suzanne J. Romano, Kevin M. Short, Deborah H. Slee, Herbert J. Fromm, Richard B. Honzatko

Biochemistry, Biophysics and Molecular Biology Publications

A highly constrained pseudo-tetrapeptide (OC252-324) further defines a new allosteric binding site located near the center of fructose-1,6-bisphosphatase. In a crystal structure, pairs of inhibitory molecules bind to opposite faces of the enzyme tetramer. Each ligand molecule is in contact with three of four subunits of the tetramer, hydrogen bonding with the side chain of Asp187 and the backbone carbonyl of residue 71, and electrostatically interacting with the backbone carbonyl of residue 51. The ligated complex adopts a quaternary structure between the canonical R- and T-states of fructose-1,6-bisphosphatase, and yet a dynamic loop essential for catalysis ...


Interaction Of Tl+ With Product Complexes Of Fructose-1,6-Bisphosphatase, Jun-Yong Choe, Scott W. Nelson, Herbert J. Fromm, Richard B. Honzatko May 2003

Interaction Of Tl+ With Product Complexes Of Fructose-1,6-Bisphosphatase, Jun-Yong Choe, Scott W. Nelson, Herbert J. Fromm, Richard B. Honzatko

Biochemistry, Biophysics and Molecular Biology Publications

The dissociation equilibrium constant for heparin binding to antithrombin III (ATIII) is a measure of the cofactor's binding to and activation of the proteinase inhibitor, and its salt dependence indicates that ionic and non-ionic interactions contribute ∼40 and ∼60% of the binding free energy, respectively. We now report that phenylalanines 121 and 122 (Phe-121 and Phe-122) together contribute 43% of the total binding free energy and 77% of the energy of non-ionic binding interactions. The large contribution of these hydrophobic residues to the binding energy is mediated not by direct interactions with heparin, but indirectly, through contacts between their ...