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Start Over Topic recombinant proteins Publication Year Range Last 50 years
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1. Characterization and Exploration of Recombinant Wheat Catalase for Improvement of Wheat-Flour-Processing Quality.

Author

Zhang Y, Chen M, Chen Y, Hou Y, and Hu SQ

Subjects
Cloning, Molecular, Fermentation, Food Quality, Gene Expression, Glutens analysis, Pichia enzymology, Pichia genetics, Rheology, Catalase genetics, Catalase metabolism, Flour, Food Handling methods, Recombinant Proteins metabolism, Triticum enzymology
Abstract

The wheat catalase gene ( wcat1) was cloned and overexpressed in Pichia pastoris. The purified wCat1 exhibits its highest activity at pH 7.5 and 35 °C with K m and V max of 22.95 mM and 0.24 μmol/min, respectively. wCat1 could markedly improve the farinographic properties of dough, with the stability time increasing and degree of softening decreasing, and enhance the rheological properties of dough. wCat1 could also elevate bread-making quality, with increased specific volume of the bread and decreased hardness, gumminess, and chewiness, which are attributable to increased amounts of SDS-insoluble protein in dough, resulting in extended glutenin networks and thus larger pores in the fermented dough and bread crumb. The decrease of hydrogen peroxide and increase of free thiol groups in wCat1-treated dough suggest that the decomposition of hydrogen peroxide by wCat1 likely promotes disulfide-bond formation and thus the cross-linking of dough proteins.

Published
2019
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2. Description of compensatory gyrA mutations restoring fluoroquinolone susceptibility in Mycobacterium tuberculosis

Author

Stéphanie Petrella, Alexandra Aubry, Nicolas Veziris, Hélène Ferrand, Claudine Mayer, Aurélie Bouige, Alix Pantel, Stéphanie Matrat, Wladimir Sougakoff, Université Pierre et Marie Curie - Paris 6 (UPMC), Microbiologie structurale - Structural Microbiology (Microb. Struc. (UMR_3528 / U-Pasteur_5)), Institut Pasteur [Paris] (IP)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre d'Immunologie et de Maladies Infectieuses (CIMI), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Parts of this paper were presented at the ‘International Conference on Antimicrobial Agents and Chemotherapy’, USA, 2011 (C1-626), and at the EMBO Conference ‘Tuberculosis 2012’, France, 2012 (TUBERCULOSIS2012/000269)., Institut Pasteur [Paris]-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre National de Référence des Mycobactéries et de la Résistance aux Antituberculeux [CHU Pitié-Salpêtrière], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Centre National de Référence des Mycobactéries et de la Résistance des Mycobactéries aux Antituberculeux, Bactériologie-Hygiène [CHU Pitié-Salpêtrière] ], and CHU Pitié-Salpêtrière [APHP]

Subjects
0301 basic medicine, MESH: Mycobacterium tuberculosis, DNA Mutational Analysis, Mutant, Antitubercular Agents, medicine.disease_cause, DNA gyrase, MESH: Recombinant Proteins, Suppression, Genetic, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Pharmacology (medical), MESH: DNA Mutational Analysis, MESH: Suppression, Genetic, MESH: Inhibitory Concentration 50, Mutation, MESH: Microbial Sensitivity Tests, biology, Chemistry, MESH: Escherichia coli, Recombinant Proteins, 3. Good health, MESH: Mutagenesis, Site-Directed, Infectious Diseases, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, DNA Gyrase, DNA supercoil, Fluoroquinolones, medicine.drug, MESH: DNA Gyrase, Microbiology (medical), 030106 microbiology, Mutation, Missense, Microbial Sensitivity Tests, Microbiology, Mycobacterium tuberculosis, Inhibitory Concentration 50, 03 medical and health sciences, Drug Resistance, Bacterial, MESH: Drug Resistance, Bacterial, Escherichia coli, medicine, Humans, Pharmacology, MESH: Mutation, Missense, MESH: Humans, Mutagenesis, MESH: Fluoroquinolones, biology.organism_classification, MESH: Antitubercular Agents, Mutagenesis, Site-Directed, [SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, Ofloxacin
Abstract

International audience; OBJECTIVES:Resistance to fluoroquinolones (FQs) in Mycobacterium tuberculosis (Mtb) is mainly due to mutations in DNA gyrase (GyrA2B2), with the most common substitutions located at positions 90 and 94 in GyrA. Two clinical MDR Mtb (MDR-TB) strains harbouring an A90E or D94N substitution in GyrA were found to be surprisingly susceptible to FQs (ofloxacin MIC ≤2 mg/L). We studied the impact of the additional GyrA substitutions found in these strains (T80A and T80A + A90G, respectively) on FQ susceptibility.METHODS:Mutants of interest were generated by site-specific mutagenesis of GyrA alleles. WT and mutant TB DNA gyrase subunits were overexpressed in Escherichia coli and purified, and the in vitro susceptibility to FQs of their DNA supercoiling reaction was studied.RESULTS:IC50s of mutant gyrase complexes bearing GyrA D94N and A90E were 3- to 36-fold higher than WT IC50s, whereas IC50s of gyrase bearing T80A + A90G + D94N and T80A + A90E were close to the WT IC50s.CONCLUSIONS:We demonstrated that substitutions T80A and A90G restore FQ susceptibility when associated with a substitution implicated in high-level FQ resistance. Line probe assay misclassification of MDR-TB strains as pre-XDR or XDR can be corrected by sequence analysis of gyrA.

Published
2016