Search

Your search keyword '"Fothergill-Gilmore, Linda A."' showing total 212 results
Start Over Author "Fothergill-Gilmore, Linda A."
212 results on '"Fothergill-Gilmore, Linda A."'

9. Structures of Leishmania Fructose-1,6-Bisphosphatase Reveal Species-Specific Differences in the Mechanism of Allosteric Inhibition

Author

Yuan, Meng, Vásquez-Valdivieso, Montserrat G., McNae, Iain W., Michels, Paul A.M., Fothergill-Gilmore, Linda A., and Walkinshaw, Malcolm D.

Subjects
Models, Molecular, crystal structure, TDA, thermal denaturation assay, Protein Conformation, plFBPase, pig liver fructose-1,6-bisphosphatase, F6P, fructose 6-phosphate, PGI, phosphoglucose isomerase, Coenzymes, Pi, phosphate, hmFBPase, human muscle fructose-1,6-bisphosphatase, Crystallography, X-Ray, Article, Allosteric Regulation, G6PDH, glucose-6-phosphate dehydrogenase, enzyme kinetics, FBPase, fructose-1,6-bisphosphatase, Humans, Enzyme Inhibitors, Allostery, Leishmaniasis, Molecular Biology, leishmaniasis, Leishmania major, Manganese, allostery, Crystal structure, Enzyme kinetics, Gluconeogenesis, Adenosine Monophosphate, TEA, triethanolamine, Fructose-Bisphosphatase, LmFBPase, Leishmania fructose-1,6-bisphosphatase, Kinetics, hlFBPase, human liver fructose-1,6-bisphosphatase, gluconeogenesis, TLS, translation libration screw, F16BP, fructose 1,6-bisphosphate, Protein Multimerization, Protein Binding
Abstract

The gluconeogenic enzyme fructose-1,6-bisphosphatase has been proposed as a potential drug target against Leishmania parasites that cause up to 20,000–30,000 deaths annually. A comparison of three crystal structures of Leishmania major fructose-1,6-bisphosphatase (LmFBPase) along with enzyme kinetic data show how AMP acts as an allosteric inhibitor and provides insight into its metal-dependent reaction mechanism. The crystal structure of the apoenzyme form of LmFBPase is a homotetramer in which the dimer of dimers adopts a planar conformation with disordered “dynamic loops”. The structure of LmFBPase, complexed with manganese and its catalytic product phosphate, shows the dynamic loops locked into the active sites. A third crystal structure of LmFBPase complexed with its allosteric inhibitor AMP shows an inactive form of the tetramer, in which the dimer pairs are rotated by 18° relative to each other. The three structures suggest an allosteric mechanism in which AMP binding triggers a rearrangement of hydrogen bonds across the large and small interfaces. Retraction of the “effector loop” required for AMP binding releases the side chain of His23 from the dimer–dimer interface. This is coupled with a flip of the side chain of Arg48 which ties down the key catalytic dynamic loop in a disengaged conformation and also locks the tetramer in an inactive rotated T-state. The structure of the effector site of LmFBPase shows different structural features compared with human FBPases, thereby offering a potential and species-specific drug target., Graphical abstract Image 1, Highlights • Leishmania fructose-1,6-bisphosphatase provides a potential drug target. • LmFBPase co-crystal structure with AMP reveals its allosteric inhibitory mechanism. • The allosteric LmFBPase is regulated by a species-specific effector loop. • AMP unlocks interface bonds to induce dimer rotation to the LmFBPase inactive form. • The poorly conserved LmFBPase AMP site offers a species-specific druggable pocket.

Published
2017

12. The active site architecture of a short-chain dehydrogenase defined by site-directed mutagenesis and structure modeling

Author

Pouplana, Lluis Ribas de and Fothergill-Gilmore, Linda A.

Subjects
Binding sites (Biochemistry) -- Research, Mutagenesis -- Research, Dehydrogenases -- Research, Drosophila -- Research, Biological sciences, Chemistry
Abstract

Structure modeling and site-directed mutagenesis help determine the active-domain architecture of a short-chain Drosophila alcohol dehydrogenase. A loop closure mechanism identical to that of lactate dehydrogenase comprises the active domain architecture. Preliminary binding of NAD in the ordered mechanism facilitates the closure of a C-terminal loop over the active domain.

Published
1994

13. An allostatic mechanism for M2 pyruvate kinase as an amino-acid sensor

Author

Yuan, Meng, McNae, Iain W, Chen, Yiyuan, Blackburn, Elizabeth A, Wear, Martin A, Michels, Paul A M, Fothergill-Gilmore, Linda A, Hupp, Ted, and Walkinshaw, Malcolm D

Subjects
amino acid regulation, allostatic regulation, enzyme mechanism, pyruvate kinase
Abstract

We have tested the effect of all 20 proteinogenic amino acids on the activity of the M2 isoenzyme of pyruvate kinase (M2PYK) and show that, within physiologically relevant concentrations, phenylalanine, alanine, tryptophan, methionine, valine, and proline act as inhibitors, while histidine and serine act as activators. Size exclusion chromatography has been used to show that all amino acids, whether activators or inhibitors, stabilise the tetrameric form of M2PYK. In the absence of amino-acid ligands an apparent tetramer-monomer dissociation Kd is estimated to be ∼0.9 µM with a slow dissociation rate (t1/2 ∼ 15 min). X-ray structures of M2PYK complexes with alanine, phenylalanine, and tryptophan show the M2PYK locked in an inactive T-state conformation, while activators lock the M2PYK tetramer in the active R-state conformation. Amino-acid binding in the allosteric pocket triggers rigid body rotations (11°) stabilising either T or R states. The opposing inhibitory and activating effects of the non-essential amino acids serine and alanine suggest that M2PYK could act as a rapid-response nutrient sensor to rebalance cellular metabolism. This competition at a single allosteric site between activators and inhibitors provides a novel regulatory mechanism by which M2PYK activity is finely tuned by the relative (but not absolute) concentrations of activator and inhibitor amino acids. Such 'allostatic' regulation may be important in metabolic reprogramming and influencing cell fate.

Published
2018

14. Pyruvate Kinase Regulates the Pentose-Phosphate Pathway in Response to Hypoxia in Mycobacterium tuberculosis

Author

Zhong, Wenhe, primary, Guo, Jingjing, additional, Cui, Liang, additional, Chionh, Yok Hian, additional, Li, Kuohan, additional, El Sahili, Abbas, additional, Cai, Qixu, additional, Yuan, Meng, additional, Michels, Paul A.M., additional, Fothergill-Gilmore, Linda A., additional, Walkinshaw, Malcolm D., additional, Mu, Yuguang, additional, Lescar, Julien, additional, and Dedon, Peter C., additional

Published
2019
Full Text
View/download PDF

18. Allosteric pyruvate kinase-based “logic gate” synergistically senses energy and sugar levels in Mycobacterium tuberculosis

Author

Zhong, Wenhe, primary, Cui, Liang, additional, Goh, Boon Chong, additional, Cai, Qixu, additional, Ho, Peiying, additional, Chionh, Yok Hian, additional, Yuan, Meng, additional, Sahili, Abbas El, additional, Fothergill-Gilmore, Linda A., additional, Walkinshaw, Malcolm D., additional, Lescar, Julien, additional, and Dedon, Peter C., additional

Published
2017
Full Text
View/download PDF

21. An allostatic mechanism for M2 pyruvate kinase as an amino-acid sensor.

Author

Meng Yuan, McNae, Iain W., Yiyuan Chen, Blackburn, Elizabeth A., Wear, Martin A., Michels, Paul A. M., Fothergill-Gilmore, Linda A., Hupp, Ted, and Walkinshaw, Malcolm D.

Subjects
AMINO acids, PYRUVATE kinase, ISOENZYMES, PHENYLALANINE, TRYPTOPHAN, LIGANDS (Biochemistry)
Abstract

We have tested the effect of all 20 proteinogenic amino acids on the activity of the M2 isoenzyme of pyruvate kinase (M2PYK) and show that, within physiologically relevant concentrations, phenylalanine, alanine, tryptophan, methionine, valine, and proline act as inhibitors, while histidine and serine act as activators. Size exclusion chromatography has been used to show that all amino acids, whether activators or inhibitors, stabilise the tetrameric form of M2PYK. In the absence of amino-acid ligands an apparent tetramer- monomer dissociation Kd is estimated to be ~0.9 μM with a slow dissociation rate (t1/2~15 min). X-ray structures of M2PYK complexes with alanine, phenylalanine, and tryptophan show the M2PYK locked in an inactive T-state conformation, while activators lock the M2PYK tetramer in the active R-state conformation. Amino-acid binding in the allosteric pocket triggers rigid body rotations (11°) stabilising either T or R states. The opposing inhibitory and activating effects of the non-essential amino acids serine and alanine suggest that M2PYK could act as a rapid-response nutrient sensor to rebalance cellular metabolism. This competition at a single allosteric site between activators and inhibitors provides a novel regulatory mechanism by which M2PYK activity is finely tuned by the relative (but not absolute) concentrations of activator and inhibitor amino acids. Such 'allostatic' regulation may be important in metabolic reprogramming and influencing cell fate. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

22. Allosteric pyruvate kinase-based "logic gate" synergistically senses energy and sugar levels in Mycobacterium tuberculosis.

Author

Wenhe Zhong, Liang Cui, Boon Chong Goh, Qixu Cai, Peiying Ho, Yok Hian Chionh, Meng Yuan, El Sahili, Abbas, Fothergill-Gilmore, Linda A., Walkinshaw, Malcolm D., Lescar, Julien, and Dedon, Peter C.

Subjects
ALLOSTERIC proteins, PYRUVATE kinase, MYCOBACTERIUM tuberculosis, METABOLOMICS, GLUCOSE 6-phosphatase, METABOLITES
Abstract

Pyruvate kinase (PYK) is an essential glycolytic enzyme that controls glycolytic flux and is critical for ATP production in all organisms, with tight regulation by multiple metabolites. Yet the allosteric mechanisms governing PYK activity in bacterial pathogens are poorly understood. Here we report biochemical, structural and metabolomic evidence that Mycobacterium tuberculosis (Mtb) PYK uses AMP and glucose-6-phosphate (G6P) as synergistic allosteric activators that function as a molecular "OR logic gate" to tightly regulate energy and glucose metabolism. G6P was found to bind to a previously unknown site adjacent to the canonical site for AMP. Kinetic data and structural network analysis further show that AMP and G6P work synergistically as allosteric activators. Importantly, metabolome profiling in the Mtb surrogate, Mycobacterium bovis BCG, reveals significant changes in AMP and G6P levels during nutrient deprivation, which provides insights into how a PYK OR gate would function during the stress of Mtb infection. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

26. Identification of ML251, a Potent Inhibitor of T. brucei and T. cruzi Phosphofructokinase

Author

Brimacombe, Kyle R., primary, Walsh, Martin J., additional, Liu, Li, additional, Vásquez-Valdivieso, Montserrat G., additional, Morgan, Hugh P., additional, McNae, Iain, additional, Fothergill-Gilmore, Linda A., additional, Michels, Paul A. M., additional, Auld, Douglas S., additional, Simeonov, Anton, additional, Walkinshaw, Malcolm D., additional, Shen, Min, additional, and Boxer, Matthew B., additional

Published
2013
Full Text
View/download PDF

27. Characterisation of active-site mutants of Schizosaccharomyces pombe phosphoglycerate mutase

Author

Nairn, Jacqueline, Duncan, Doris, Price, Naomi E, Kelly, Sharon M, Fothergill-Gilmore, Linda A, Uhrinova, Stanislava, Barlow, Paul N, Rigden, Daniel J, and Price, Nicholas C

Subjects
phosphoglycerate mutase, Amino acids Metabolism, protein stability, Mutagenesis, substrate binding, catalytic mechanism, site-directed mutagenesis, Yeast
Abstract

The roles of a number of amino acids present at the active site of the monomeric phosphoglycerate mutase from the fission yeast Schizosaccharomyces pombe have been explored by site-directed mutagenesis. The amino acids examined could be divided broadly into those presumed from previous related structural studies to be important in the catalytic process (R14, S62 and E93) and those thought to be important in substrate binding (R94, R120 and R121). Most of these residues have not previously been studied by site-directed mutagenesis. All the mutants except R14 were expressed in an engineered null strain of Saccharomyces cerevisiae (S150-gpm::HIS) in good yield. The R14Q mutant was expressed in good yield in the transformed AH22 strain of S. cerevisiae. The S62A mutant was markedly unstable, preventing purification. The various mutants were purified to homogeneity and characterized in terms of kinetic parameters, CD and fluorescence spectra, stability towards denaturation by guanidinium chloride, and stability of phosphorylated enzyme intermediate. In addition, the binding of substrate (3-phosphoglycerate) to wild-type, E93D and R120,121Q enzymes was measured by isothermal titration calorimetry. The results provide evidence for the proposed roles of each of these amino acids in the catalytic cycle and in substrate binding, and will support the current investigation of the structure and dynamics of the enzyme using multidimensional NMR techniques

Published
2000

29. A new family of covalent inhibitors block nucleotide binding to the active site of pyruvate kinase

Author

Morgan, Hugh P., primary, Walsh, Martin J., additional, Blackburn, Elizabeth A., additional, Wear, Martin A., additional, Boxer, Matthew B., additional, Shen, Min, additional, Veith, Henrike, additional, McNae, Iain W., additional, Nowicki, Matthew W., additional, Michels, Paul A. M., additional, Auld, Douglas S., additional, Fothergill-Gilmore, Linda A., additional, and Walkinshaw, Malcolm D., additional

Published
2012
Full Text
View/download PDF

33. Glycolytic Enzymes

Author

Michels, Paul AM, primary, Verlinde, Christophe LMJ, additional, and Fothergill‐Gilmore, Linda A, additional

Published
2010
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results