Refaat Hamed
Assiut University, Natural Products Chemistry, Faculty Member
- Chemistry, Biosynthesis of Natural Products, Biocatalysis, Fermentation Technology, Protein engineering, Chemical Biology, NMR Spectroscopy, Mass Spectrometry, and 18 moreOrganic Chemistry, Pharmacognosy, Technology, Bioinformatics, Medicinal Chemistry, Protein Purification, Crystallography, Structure Based Drug Design, Protein expression/purifucation, Enzyme Inhibitors, Natural Products Chemistry, Macromolecular crystallography, Macromolecular X-Ray Crystallography, Thermostable Enzymes, Enzyme Characterisation, Drug Targetting Techniques, Crystals Structure Interpretation, and Thermostable Proteinedit
The use of methylmalonyl-CoA epimerase (MCEE) to improve stereoselectivity in crotonase-mediated biocatalysis is exemplified by the coupling of MCEE, crotonyl-CoA carboxylase reductase and carboxymethylproline synthase in a three-enzyme... more
The use of methylmalonyl-CoA epimerase (MCEE) to improve stereoselectivity in crotonase-mediated biocatalysis is exemplified by the coupling of MCEE, crotonyl-CoA carboxylase reductase and carboxymethylproline synthase in a three-enzyme one-pot sequential synthesis of functionalised C-5 carboxyalkylprolines starting from crotonyl-CoA and carbon dioxide.
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ABSTRACT A process for preparing an enantiomerically enriched compound containing a substituted heterocyclic ring, said process comprising a carbon-carbon bond formation reaction in the presence of a crotonase superfamily protein or a... more
ABSTRACT A process for preparing an enantiomerically enriched compound containing a substituted heterocyclic ring, said process comprising a carbon-carbon bond formation reaction in the presence of a crotonase superfamily protein or a homolog or variant thereof.
FIH (Factor inhibiting hypoxia-inducible factor), an asparaginyl beta-hydroxylase belonging to the super-family of 2-oxoglutarate and Fe(II)-dependent dioxygenases, catalyses hydroxylation of Asn-803 of hypoxia-inducible factor, a... more
FIH (Factor inhibiting hypoxia-inducible factor), an asparaginyl beta-hydroxylase belonging to the super-family of 2-oxoglutarate and Fe(II)-dependent dioxygenases, catalyses hydroxylation of Asn-803 of hypoxia-inducible factor, a transcription factor that regulates the mammalian hypoxic response. Only one other asparaginyl beta-hydroxylase, which catalyses hydroxylation of both aspartyl and asparaginyl residues in EGF (epidermal growth factor)-like domains, has been characterized. In the light of recent crystal structures of FIH, we compare FIH with the EGFH (EGF beta-hydroxylase) and putative asparagine/asparaginyl hydroxylases. Sequence analyses imply that EGFH does not contain the HXD/E iron-binding motif characteristic of most of the 2-oxoglutarate oxygenases.
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Research Interests:
Research Interests:
Research Interests:
Structural and mechanistic studies on the crotonase superfamily (CS) are reviewed with the aim of illustrating how a conserved structural platform can enable catalysis of a very wide range of reactions. Many CS reactions have precedent in... more
Structural and mechanistic studies on the crotonase superfamily (CS) are reviewed with the aim of illustrating how a conserved structural platform can enable catalysis of a very wide range of reactions. Many CS reactions have precedent in the ‘carbonyl’ chemistry of organic synthesis; they include alkene hydration/isomerization, aryl-halide dehalogenation, (de)carboxylation, CoA ester and peptide hydrolysis, fragmentation of β-diketones and C-C bond formation, cleavage and oxidation. CS enzymes possess a canonical fold formed from repeated ββα units that assemble into two approximately perpendicular β-sheets surrounded by α-helices. CS enzymes often, although not exclusively, oligomerize as trimers or dimers of trimers. Two conserved backbone NH groups in CS active sites form an oxyanion ‘hole’ that can stabilize enolate/oxyanion intermediates. The range and efficiency of known CS-catalyzed reactions coupled to their common structural platforms suggest that CS variants may have widespread utility in biocatalysis.
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Research Interests:
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