R67 dihydrofolate reductase (DHFR) catalyzes the reduction of dihydrofolate (DHF) to tetrahydrofolate using NADPH as a cofactor. This enzyme is a homotetramer possessing 222 symmetry, and a single active site pore traverses the length of the protein. A promiscuous binding surface can accommodate either DHF or NADPH, thus two nonproductive complexes can form (2NADPH or 2DHF) as well as a product...

In the present study, the effect of seed priming with magnetic field (MF; 45, 90, 200 and 250mT for 5, 10, 20 and 30 min) was evaluated in 60-day-old Hyssopus officinalis plants grownunder 8 days irrigation intervals. The assessments were consisted of biomass, membranestability, photosynthetic pigments concentrations, polyphenols content, antioxidant enzymesactivities an...

Abstract Growth of bionanotechnology requires functional materials, which can lower the costs and be modified to specific reaction. Conjugations nanoparticles enzymes form efficient products multi-material enzyme-nanocomplexes, controlled from synthesis application provide predicted results. Multimetallic nanooxides ZnO–CuO, ZnO–MnO, ZnO–MnO–CuO were obtained by precipitation method with sonica...

In order to understand the response of tobacco to salt stress, antioxidant enzyme activities, plant biomass and ion content were analyzed in two oriental tobacco genotypes (Basma 31 and SPT 406). Tobacco plants were exposed to 0, 50, 100, 150 and 200 mM NaCl for 12 days. The fresh and dry weight as well as shoot and root length of Basma 31 were greater than those of SPT 406 under increasing sal...

In order to study the effect of external ethylene on postharvest display and activity of some senescence-related enzymes in potted miniature roses, this experiment was carried out in a completely randomized design, using three treatment levels with three replications. In glass chambers, potted miniature rose plants were exposed to ethylene concentrations of 0, 5 and 10 μL L-1 for 12 h. The resu...

Marine invertebrates exposed to high levels of reactive oxygen species in the oceans have been reported to produce antioxidants as a major defense against free radical mediated toxicity; protecting their tissues from the damage associated with the oxidative stress. In view of this, the present study was carried out to determine the antioxidant activity of 100 bacterial bionts isolated from mari...

Background: Nowadays, natural antioxidants are used to replace synthetic antioxidants for delaying or preventing the oxidation of edible oils. In this study, phenolic compounds and antioxidant properties of methanol extracts of Spirulina microalgae (Arthrospira platensis) were measured. Methods: Phenolic content was measured by Folin–Ciocalteau method and antioxidant activity was measured by th...

conclusions according to the obtained data, synthesized pyridine based chalcones (3a-3j) could be proposed as potential antioxidant lead compounds. background natural chalcones and also their synthetic derivatives have attracted increasing attention due to various pharmacological applications. development and discovery of new chalcones with antioxidant activities is one of the attracting areas ...