Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The objective of the study was to compare three different oxidizing systems commonly present in muscle foods for their influence on the biochemical properties of muscle proteins. Myofibrillar protein isolate (MPI) prepared from pork serratus ventralis muscle was suspended (30 mg protein/mL) in 15 mM piperazine-N,N-bis(2-ethane sulfonic acid) buffer (pH 6.0). Oxidation was induced by incubating the protein suspension at 4 degrees C for 24 h with (i) a hydroxyl radical-generating system (HRGS: 10 microM FeCl3, 0.1 mM ascorbic acid, and 0.05-5.0 mM H2O2), (ii) a lipid-oxidizing system (LOS: 0.05-5.0 mM linoleic acid and 3750 units of lipoxidase/mL), or (iii) a metmyoglobin-oxidizing system (MOS: 0.05-0.5 mM metmyoglobin). Changes in oxidized MPI were measured as Ca- and K-ATPase activities, formation of protein carbonyls and 2-thiobarbituric acid-reactive substances (TBARS), loss of protein thermal stability, and protein aggregation. The three oxidizing matrixes induced complex MPI changes; for example, the Ca- and K-ATPase activities were altered mainly by low-concentration oxidants, but the changes were unique for each oxidizing system. The carbonyl content in MOS-treated MPI was the highest, while the TBARS production, changes in thermal properties, and loss of the myosin heavy chain were the greatest in HRGS-treated MPIs. Overall, the hydroxyl radical-producing medium appeared to be the most oxidative to myofibrillar proteins under the experimental conditions employed in the study.
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PMID:Biochemical changes in myofibrillar protein isolates exposed to three oxidizing systems. 1675 79

The JAK2(V617F) mutation is frequently observed in classical myeloproliferative disorders, and disease progression is associated with a biallelic acquisition of the mutation occurring by mitotic recombination. In this study, we examined whether JAK2 activation could lead to increased homologous recombination (HR) and genetic instability. In a Ba/F3 cell line expressing the erythropoietin (EPO) receptor, mutant JAK2(V617F) and, to a lesser extent, wild-type (wt) JAK2 induced an increase in HR activity in the presence of EPO without modifying nonhomologous end-joining efficiency. Moreover, a marked augmentation in HR activity was found in CD34(+)-derived cells isolated from patients with polycythemia vera or primitive myelofibrosis compared with control samples. This increase was associated with a spontaneous RAD51 foci formation. As a result, sister chromatid exchange was 50% augmented in JAK2(V617F) Ba/F3 cells compared with JAK2wt cells. Moreover, JAK2 activation increased centrosome and ploidy abnormalities. Finally, in JAK2(V617F) Ba/F3 cells, we found a 100-fold and 10-fold increase in mutagenesis at the HPRT and Na/K ATPase loci, respectively. Together, this work highlights a new molecular mechanism for HR regulation mediated by JAK2 and more efficiently by JAK2(V617F). Our study might provide some keys to understand how a single mutation can give rise to different pathologies.
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PMID:JAK2 stimulates homologous recombination and genetic instability: potential implication in the heterogeneity of myeloproliferative disorders. 1851 59

The objective of the study was to investigate the role of hydrolyzed potato protein (HPP) in protecting myofibril protein isolate (MPI) from oxidative modification. MPI prepared from pork muscle was suspended (30 mg protein/mL) in 15 mM piperazine-N, N-bis(2-ethane sulfonic acid) buffer (pH 6.0) with 0, 0.3, 0.75, and 1.5 mg/mL of antioxidative HPP (1-h Alcalase hydrolysate). Oxidation was induced by incubating the protein suspensions at 4 degrees C for 24 h with (1) an iron-catalyzed oxidizing system (IOS: 0.01 mM FeCl3, 0.1 mM ascorbic acid, and 1.0 mM H202) and (2) a metmyoglobin-oxidizing system (MOS: 0.1 mM metmyoglobin and 0.1 mM H2O2). Changes in oxidized MPI were measured as thiobarbituric acid-reactive substances (TBARS), protein carbonylcontent, Ca- and K-ATPase activities, and ultraviolet (UV) spectra. Oxidation increased the production of TBARS and protein carbonyls by 2.9- and 0.24-fold in IOS and 5.6- and 2.2-fold in MOS, respectively. The 2 oxidizing systems altered the Ca- and K-ATPase activities and exposed hydrophobic groups buried in MPI. The presence of HPP reduced the extent of MPI oxidation in all physicochemical categories tested. Therefore, HPP may be used as a potential functional ingredient in meat products to enhance their oxidative stability.
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PMID:Inhibition of oxidant-induced biochemical changes of pork myofibrillar protein by hydrolyzed potato protein. 1924 38