Some kinetic properties of a purified glutamine synthetase from bacteroids of Glycine max

Abstract A purified glutamine synthetase was prepared from bacteroids of Rhizobium japonicum from nodules of Glycine max . For the biosynthetic assay the K _m values (mM) were l -glutamate 12.9, NH₄Cl 8.9 and ATP 14.3. When the enzyme was assayed by the γ-glutamyltransferase reaction the K _m values (mM) were l -glutamine 11.1 and hydroxylamine 3.3 compared with 7.7 and 1.2, respectively, for the purified enzyme from Rhizobium japonicum grown in culture. The enzyme prepared from bacteroids of Glycine max was 80% adenylylated.     

Isolation of autosomal mutations in Drosophila melanogaster without setting up lines

Summary Mutants of Drosophila melanogaster are being used increasingly for studying different biological mechanisms. However, most attempts to identify new mutations have been restricted to the X-chromosome. It has been very difficult to identify new loci on the autosomes, as recessive mutations have to be made homozygous by setting up independent cultures for each mutagenized chromosome. We introduce a mutagenesis scheme which does not require setting up independent cultures. It uses meiotic recombination in compound autosomes to make recessive mutations homozygous and allows the screening of tens of thousands of mutagenized chromosomes with relatively little effort. In a pilot experiment, we tested about 33,300 chromosomes for temperature-sensitive paralytic mutations. We obtained 62 independent paralytic mutations and a large number of other mutations. Eight out of 25 of the paralytic mutations are on the autosomes. This method makes autosomes, which constitute about 80% of the Drosophila genome, more accessible for mutational analysis of various biological mechanisms.     

Self-incompatibility: a targeted,unexplored pre-fertilization barrier in flower crops of Asteraceae

Journal of Plant Research - Asteraceae (synonym as Compositae) is one of the largest angiosperm families among flowering plants comprising one-tenth of all agri-horticultural species grown across...     

Haptoglobin patterns in essential hypertension and associated conditions--increased risk for Hp 2-2

Blood samples from 257 hypertensive patients and 180 normotensive controls were analysed for their association with haptoglobin levels and phenotypes. Compared to controls, patients with Hp 2-2 phenotype showed a significantly increased risk for essential hypertension (p less than 0.001) and hypertension associated with ischaemic heart disease (p less than 0.05). There was a significant decrease in the mean levels of serum haptoglobins in hypertension as compared to controls, suggesting the possibility for intravascular haemolysis due to vascular damage leading to further complications.     

Sunlight-driven rapid and facile synthesis of Silver nanoparticles using Allium ampeloprasum extract with enhanced antioxidant and antifungal activity

Green nanotechnology has acquired immense demand due to its cost-effective, eco-friendly and benevolent approach for the synthesis of nanoparticles. Among the biological methods, plants aid as a significant green resource for synthesizing nanoparticles that are safe and non-toxic for human use. In the present investigation, Silver nanoparticles (AgNPs) were synthesized using bulbs extract of Allium ampeloprasum under the influence of sunlight irradiation and characterized using different techniques. Distinct in-vitro assays were performed to test the antioxidant and anticandida potential of the synthesized AgNPs. Results suggested the efficient and rapid sunlight-driven synthesis of AgNPs using A. ampeloprasum extract. UV–Vis spectrum showed absorption peak at 446 nm which confirmed the formation of AgNPs. FTIR analysis suggested the presence of functional groups associated with flavonoids and sulfur compounds in A. ampeloprasum extract. The synthesized AgNPs showed Face Centred Cubic (FCC) structure with an average size of 35 nm. Spherical, quasi spherical, triangular and ellipsoidal morphology of the NPs were observed from the TEM micrograph. The synthesized AgNPs showed pronounced free radical scavenging potential for DPPH, ABTS?+ and H₂O₂ radicals. The anticandida potency of the synthesized AgNPs was observed as follows: C. albicans ≥ C. tropicalis ≥ C. glabrata ≥ C. parapsilosis ≥ C. krusei. Results showed that sunlight driven nanoparticle synthesis of AgNPs is rapid, facile and exhibit enhanced antioxidant and antifungal activity.     

Characterization of phospholipase A2 of mycoplasma species

As phospholipases of mycoplasma species may play a role in the pathogenesis of respiratory tract and urogenital tract diseasesMycoplasma mycoides andAcholeplasma laidlawii were examined as to the production of phospholipase A₂ (PLA) and attempts were made to purify and characterize it. Both species produced PLA. The purified enzyme was found to be heat-labile, active at alkaline pH, revealing a single band in polyacrylamide gel electrophoresis. Metal ions such as calcium and barium, increased its activity whereas solvents at high concentrations decreased it. It was resistant to surfactants.