Search results for "Enzymology"
showing 10 items of 60 documents
APOBEC4 Enhances the Replication of HIV-1
2016
APOBEC4 (A4) is a member of the AID/APOBEC family of cytidine deaminases. In this study we found a high mRNA expression of A4 in human testis. In contrast, there were only low levels of A4 mRNA detectable in 293T, HeLa, Jurkat or A3.01 cells. Ectopic expression of A4 in HeLa cells resulted in mostly cytoplasmic localization of the protein. To test whether A4 has antiviral activity similar to that of proteins of the APOBEC3 (A3) subfamily, A4 was co-expressed in 293T cells with wild type HIV-1 and HIV-1 luciferase reporter viruses. We found that A4 did not inhibit the replication of HIV-1 but instead enhanced the production of HIV-1 in a dose-dependent manner and seemed to act on the viral L…
Anti-prothrombin autoantibodies enriched after infection with SARS-CoV-2 and influenced by strength of antibody response against SARS-CoV-2 proteins
2021
Antiphospholipid antibodies (aPL), assumed to cause antiphospholipid syndrome (APS), are notorious for their heterogeneity in targeting phospholipids and phospholipid-binding proteins. The persistent presence of Lupus anticoagulant and/or aPL against cardiolipin and/or β2-glycoprotein I have been shown to be independent risk factors for vascular thrombosis and pregnancy morbidity in APS. aPL production is thought to be triggered by–among other factors–viral infections, though infection-associated aPL have mostly been considered non-pathogenic. Recently, the potential pathogenicity of infection-associated aPL has gained momentum since an increasing number of patients infected with Severe Acu…
New insights into the regulatory mechanisms of ppGpp and DksA on Escherichia coli RNA polymerase-promoter complex
2015
The stringent response modulators, guanosine tetraphosphate (ppGpp) and protein DksA, bind RNA polymerase (RNAP) and regulate gene expression to adapt bacteria to different environmental conditions. Here, we use Atomic Force Microscopy and in vitro transcription assays to study the effects of these modulators on the conformation and stability of the open promoter complex (RPo) formed at the rrnA P1, rrnB P1, its discriminator (dis) variant and lambda pR promoters. In the absence of modulators, RPo formed at these promoters show different extents of DNA wrapping which correlate with the position of UP elements. Addition of the modulators affects both DNA wrapping and RPo stability in a promo…
Material docente en inglés. Part III. Enzymology
2021
The present document summarizes main ideas and concepts related to enzymology and lipid structure, function and metabolism. This academic document is addressed to medical students for the study of biochemistry.
The role of enzymes in biomineralization processes.
2008
56 pages; International audience
Optimization for the determination of enzyme activities in various pea tissues
2014
Rapport de Stage de Master 1 EA Geapsi CT2 EA EJ1; In an environmental and political context which requests an increase of food production and a decrease in fertilizer use, pea culture seems to be one solution due on the one hand to its atmospheric nitrogen fixation and on the other hand to the important nitrogen quantity left by plants in the soil after harvest. But pea plants are very sensitive to soil water stress, that’s why scientists are searching information about enzyme activities to reveal how peas react when they are submitted to drought in the purpose of minimizing the negative impact and thus reach optimum yields. This report focuses on key enzymes involved in carbon and nitroge…
Procollagen C-proteinase Enhancer Stimulates Procollagen Processing by Binding to the C-propeptide Region Only*
2011
Background: Procollagen C-proteinase enhancer-1 (PCPE-1) is an extracellular glycoprotein that increases activity of certain zinc metalloproteinases involved in tissue development and repair. Results: PCPE-1 binds uniquely to the C-propeptide region of the procollagen molecule. Conclusion: PCPE-1 enhances proteolysis by binding solely to the procollagen C-propeptides. Significance: These data may lead to future applications in the development of antifibrotic therapies.
Loss of Hyperconjugative Effects Drives Hydride Transfer during Dihydrofolate Reductase Catalysis
2019
Hydride transfer is widespread in nature and has an essential role in applied research. However, the mechanisms of how this transformation occurs in living organisms remain a matter of vigorous debate. Here, we examined dihydrofolate reductase (DHFR), an enzyme that catalyzes hydride from C4′ of NADPH to C6 of 7,8-dihydrofolate (H2F). Despite many investigations of the mechanism of this reaction, the contribution of polarization of the π-bond of H2F in driving hydride transfer remains unclear. H2F was stereospecifically labeled with deuterium β to the reacting center, and β-deuterium kinetic isotope effects were measured. Our experimental results combined with analysis derived from QM/MM si…
Seminar 2_Clinical Enzimology
2022
Este documento ha sido revisado por el Servicio de política Linguística. Su labor ha sido muy importante para la correción del documento. Este documento contiene un pdf con las diapositivas utilizadas para el seminario 2, dentro de la asignatura de Integración de Bioquímica y Biología Molecular, para los alumnos de 2º curso del grado de Medicina. El seminario habla de los ensayos clínicos realizados en sangre, del valor diagnóstico de determinadas activades enzimáticas, y como realizar correctamente un análisis de sangre. Una segunda parte de este seminario trata sobre las isoenzimas. This document contains a pdf with the slides used for the seminar 2, within the subject of Integration of B…
Double copies of blaKPC-3::Tn4401a on an IncX3 plasmid in Klebsiella pneumoniae successful clone ST512 from Italy
2015
ABSTRACT A carbapenem-resistant sequence type 512 (ST512) Klebsiella pneumoniae carbapenemase 3 (KPC-3)-producing K. pneumoniae strain showing a novel variant plasmid content was isolated in Palermo, Italy, in 2014. ST512 is a worldwide successful clone associated with the spread of bla KPC genes located on the IncFIIk pKpQIL plasmid. In our ST512 strain, the bla KPC-3 gene was unusually located on an IncX3 plasmid, whose complete sequence was determined. Two copies of bla KPC-3 ::Tn 4401a caused by intramolecular transposition events were detected in the plasmid.