NOPR Collection:

Rhizobial lipopolysaccharide as the receptor in lectin-Rhizobium interaction

2004-04-01T00:00:00Z

Title: Rhizobial lipopolysaccharide as the receptor in lectin-Rhizobium interaction Authors: Bhattacharya, Indranil; Biswas, Sagarika; Das, Rakha H; Das, Hasi R Abstract: Rhizobial specificity was examined on the basis of interaction between legume lectins (peanut, pea and soybean) and different rhizobial species (various bradyrhizobia specific for peanut, P 14-93 and SB16). Legume lectins showed higher affinity towards host-specific Rhizobium and lipopolysaccharides (LPS) isolated from those particular rhizobia. Two LPS mutants of peanut-specific Bradyrhizobium sp. (Arachis) strain GN17 were isolated by Tn5 mutagenesis. These mutants (GN17MI and GNI7M2) were characterized by their higher hydrophobicity with respect to the parent cells. The hexose content in exopolysaccharides. (EPS) and LPS of the mutants was found reduced significantly, whereas 2-keto-3-deoxyoctulosonic acid (Kdo) and uronic acid in LPS were less by 20-times and thrice, respectively in the mutants. Glucose was the major sugar in LPS from all the strains. However, glucosamine appeared only in the mutants. Spectrofluorimetric analysis showed that LPS from GN17Ml mutant interacted most significantly with peanut root agglutinin or lectin (PRA II). The results indicate that LPS on the surface of rhizobial cells is the possible receptor for lectin. Page(s): 89-95

An insight into molecular mechanism of endocytosis

2004-04-01T00:00:00Z

Title: An insight into molecular mechanism of endocytosis Authors: Neekhra, Nidhi; Padh, Harish Abstract: Endocytosis involving pinocytosis, phagocytosis and receptor-mediated pathway is a central process involved in numerous cellular events: receptor recycling, nutrient uptake, transcytosis, antigen processing and presentation, pathogen uptake etc. Traditionally, the process has been studied using uptake kinetics and immunocytochemistry. In last few decades, additional tools, like mutant analysis, density shift, semi-intact and cell-free systems and electromagnetic separation have helped us to obtain molecular insight into many of the' steps involved in endocytosis. New chemical entities, like clathrin and coatomer proteins involved in internalization have been fully characterized. Biomolecules involved in vesicle budding diffusion reactions, like ARF (ADP ribosylation factors), COPs (coal proteins), and SNAREs (soluble N-ethylmaleimide sensitive factor attachment protein receptors) have been identified and characterized. Compartment specific molecules, like Rab have also added to our understanding of complex process of endocytosis. Collectively these have led us to an era of molecular endocytosis. The present review gives an overview of the process and describes some of the molecular events of the endocytic process. It also describes methods and approaches used in deciphering the events at cellular and molecular levels. Page(s): 69-80

Measurement of urinary oxalate by grain sorghum leaf oxalate oxidase immobilized to affixed alkylamine glass beads

2004-04-01T00:00:00Z

Title: Measurement of urinary oxalate by grain sorghum leaf oxalate oxidase immobilized to affixed alkylamine glass beads Authors: Kumari, M; Pundir, C S Abstract: Oxalate in urine was measured by grain Sorghum leaf oxalate oxidase conjugated to alkyl amine glass beads affixed in a beaker. The minimum detection limit was 0.05 mM/L in urine. Recovery of added oxalate in urine was 80.5% and within and between assay, coefficients of variation (CV) were <4% and <5.5%, respectively. Urinary oxalate values obtained by the present method showed a good correlation (r = 0.947) with those by Sigma kit method. The method is not only free from tedious handling of free glass beads and Cl⁻ interference, but also has longer stability and reusability of immobilized enzyme compared to that of barley root and forage Sorghum leaf. Page(s): 102-106

Absorption spectral study of 3, 4-dihydroxy phenyl alanine (DOPA) with Nd (III) in aqueous medium

2004-04-01T00:00:00Z

Title: Absorption spectral study of 3, 4-dihydroxy phenyl alanine (DOPA) with Nd (III) in aqueous medium Authors: Bhatt, Prashant N; Pathak, Trupti V; Mehta, Jignasu P; Misra, Sudhindra N Abstract: Spectroscopic properties of Nd (III)-DOPA in aquated organic solvents are investigated through absorption difference and comparative absorption spectroscopy involving 4f-4f transitions. The change in coordination in different conditions is observed from the absorption intensity analysis when Nd (III) interacts with DOPA. The interaction induced substantial changes in the intensities of 4f-4f bands and their perturbation was reflected through oscillator strength Judd-Ofelt intensity (T) parameters. It is suggested that the changes in the oscillator strengths of different 4f-4f bands and Judd-Ofelt intensity (T) parameters can be used to predict in vivo intracellular complexation of DOPA with Ca(II) through Nd (III)-DOPA absorption spectral studies in-vitro as both Nd (III) and Ca(II) have unique similarity in their coordination behaviour. Page(s): 123-127