A5054396326- Metal-Catalyzed Oxygenation Mechanisms
- Mitochondrial Function and Pathology
- Ion channel regulation and function
- Metalloenzymes and iron-sulfur proteins
- Genetic Neurodegenerative Diseases
- Genetics, Aging, and Longevity in Model Organisms
- Cholinesterase and Neurodegenerative Diseases
- Heat shock proteins research
- Crystallization and Solubility Studies
- Protein Structure and Dynamics
- Receptor Mechanisms and Signaling
- X-ray Diffraction in Crystallography
- Gout, Hyperuricemia, Uric Acid
- Enzyme Structure and Function
- Chemical Synthesis and Analysis
- Glutathione Transferases and Polymorphisms
- Cardiac electrophysiology and arrhythmias
- Virus-based gene therapy research
- Health Systems, Economic Evaluations, Quality of Life
- Prion Diseases and Protein Misfolding
- Animal testing and alternatives
- Supramolecular Self-Assembly in Materials
- Biopolymer Synthesis and Applications
- Oral microbiology and periodontitis research
- Genomics, phytochemicals, and oxidative stress
University of Malta
2010-2024
Imam Abdulrahman Bin Faisal University
2023
Temple University
2020
University of Nottingham
2003
Cranfield University
1997
Washington University in St. Louis
1949
Two genes encoding manganese superoxide dismutase (sod-2 and sod-3) have been identified in the nematode Caenorhabditis elegans. Each gene is composed of five exons, intron positions are identical; however, sizes sequences not same. The predicted protein 86.3% homologous (91.8% conservative), cDNAs only 75.2% homologous. Both deduced contain expected N-terminal mitochondrial transit peptides. Reverse transcriptase polymerase chain reaction analysis shows that both expressed under normal...
We have expressed, purified, and analyzed the iron-containing superoxide dismutase (FeSOD) of Escherichia coli with mutations directed at tyrosine position 34 to introduce phenylalanine (SODY34F), serine (SODY34S), or cysteine (SODY34C). FeSOD mutant enzymes were purified from SOD-deficient cells using a GST-FeSOD fusion protein intermediate which was subsequently cleaved thrombin repurified. Specific activities measured xanthine-xanthine oxidase method gave 3148 u/mg for wild-type FeSOD....
Muscarinic receptors are a functionally important family of G-protein-coupled receptors. Using combination rapid amplification 5' cDNA ends and reporter gene assays, we characterized the untranslated region CHRM2 as expressed in human airway smooth muscle (HASM) cells. A splice site is present 46 bp upstream from ATG start codon. Five exons with alternative splicing patterns this site, separated by introns ranging 87 to > 145 kb. There evidence for being under control TATA-less promoter Sp1,...
Channelopathy mutations prove informative on disease causing mechanisms and channel gating dynamics. We have identified a novel heterozygous mutation in the KCNA1 gene of young proband displaying typical signs symptoms Episodic Ataxia type 1 (EA1). This is S4 helix voltage-sensing domain results substitution highly conserved phenylalanine 303 by valine (p.F303V). The contributions F303 towards K+ voltage are unclear here been assessed biophysically performing structural analysis using rat...
Abstract C. elegans MnSOD‐3 has been implicated in the longevity pathway and its mechanism of catalysis is relevant to aging process carcinogenesis. The structures provide unique crystallographic evidence a dynamic region tetrameric interface (residues 41–54). We have determined structure MnSOD‐3‐azide complex 1.77‐Å resolution. Analysis this shows that substrate analog, azide, binds end‐on manganese center as sixth ligand it ligates directly third new solvent molecule also positioned within...
The structurally homologous mononuclear iron and manganese superoxide dismutases (FeSOD MnSOD, respectively) contain a highly conserved glutamine residue in the active site which projects toward active‐site metal centre participates an extensive hydrogen bonding network. position of this is different for each SOD isoenzyme (Q69 FeSOD Q146 MnSOD Escherichia coli ). Although site‐directed mutant enzymes lacking (FeSOD[Q69G] MnSOD[Q146A]) demonstrated higher degree selectivity their respective...
Superoxide dismutase (SOD)-deficient Escherichia coli OX326Acells are protected against chemically-induced oxidative stress by expression of the chaperonin GroESL. This protection is equivalent to superoxide even though GroESL has no inherent SOD activity. Co-overexpression and in same cells results higher protein yields greater metallation when compared with alone. Greater specific activity that observed heat shock, not due increased synthesis mRNA or protein.
Caenorhabditis elegans expresses two manganese superoxide dismutase enzymes (MnSOD-2 and MnSOD-3) that are targeted to the mitochondrion. MnSOD-2 is constitutively expressed, while synthesis of MnSOD-3 inducible. The structures these mononuclear metalloenzymes have been determined 1.8 1.7 A resolution, respectively. Pink crystals formed in space group P4(1)2(1)2 for each, with unit-cell parameters a = b 81.0, c 137.4 81.8, 136.0 MnSOD-3. final structure was refined R 21.6% R(free) 26.2% at...
A series of recent studies have provided initial evidence about the role specific intra-molecular interactions in maintaining proteins their soluble state and protecting them from aggregation. Here we show that amino acid sequence protein monellin contains two aggregation-prone regions are prevented initiating aggregation by multiple non-covalent favor burial within folded protein. By investigating behavior single-chain a five its mutational variants using variety biochemical, biophysical...
We have generated a site-directed mutant of the manganese superoxide dismutase SOD-3 C.elegans (MnSOD-3) which modifies metal specificity enzyme. While wild-type MnSOD-3 functions with in active site (3600 U mg-1 protein) it has little or no activity when iron is incorporated. However, histidine replaces glutamine 142 site, enzyme retains 50 % its and becomes cambialistic for cofactor exhibiting very similar specific either iron.
Superoxide dismutases are antioxidant scavenger enzymes that contain a metal cofactor (copper, zinc, iron, and manganese) in their active site. Metal content measurement is one of the essential steps to characterize enzyme biological activity. We have developed capillary electrophoretic protocol for determination superoxide dismutase enzymes. The background electrolyte containing 10 mM pyridine-2,6-dicarboxylic acid 1 1-methyl-3-tetradecylimidazolium chloride at pH 3.8 was optimized...
We have generated a mutant of C. elegans manganese superoxide dismutase at histidine 30 by site-directed mutagenesis. The structure was solved resolution 1.52 Å X-ray crystallography (pdb: 6S0D). His30 targeted, as it forms gateway residue the top solvent access funnel to active site, together with Tyr34. In wild-type protein, these residues are involved in hydrogen-bonding network providing protons necessary for catalytic reaction metal center. However, biophysical characterization and cell...
Xanthine oxidoreductase (XOR) is a molybdoflavoprotein mainly involved in purine catabolism. It exists two forms, the oxidase (XO) and dehydrogenase (XDH) which are inter-convertible within mammalian cells. Although various researchers have reported extraction of XOR, no extractions yet been carried out Malta subsequently characterizations available. In this study, XOR was successfully purified from bovine, caprine ovine milk through multistep purification process involving both chemical...
Mathematical models are necessary to understand how the material composition of biofilms can influence their physical properties. Here, we developed a 4D computational toolchain for analysis bead trajectories, which laid groundwork establishing critical parameters mathematical particle movement in biofilms. Using this open-source trajectory analyzer, determined that presence bacterial amyloid curli changes properties biofilm, making biofilm matrix rigid. This software is powerful tool...