http://nopr.niscair.res.in/handle/123456789/3233 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/3279 Title: Bemisia tabaci feeding induces pathogenesis-related proteins in cassava (Manihot esculenta Crantz) <br/> <br/>Authors: Antony, Binu; Palaniswami, M S <br/> <br/>Abstract: Cassava (Manihot esculenta Cranzts) plants fed upon by whitefly Bemisia tabaci showed increased levels of pathogenesis-related (PR) proteins, such as β-1, 3-glucanase, peroxidase and chitinase activities, as compared to uninfested plants. The enzymes increased in specific activities from 2 to 7 fold and protein content in leaf extracts decreased in whitefly-infested plants, compared to uninfested plants. Among the three PR proteins, B. tabaci feeding induced significantly higher β-1, 3-glucanase activities, when compared with other two PR proteins. Study also discussed the possible application of PR proteins in whitefly control program. <br/> <br/>Page(s): 182-185 http://nopr.niscair.res.in/handle/123456789/3278 Title: Vibrational dynamics of morphine in relation to Leu⁵- and Met⁵-enkephalins <br/> <br/>Authors: Misra, Neeraj; Prasad, Onkar; Sinha, Leena <br/> <br/>Abstract: A complete normal coordinate analysis of morphine using Wilson’s GF matrix method and Urey Bradley force field has been carried out to understand the dynamical behaviour of morphine in relation to Leu⁵- and Met⁵-enkephalins. In addition, charge distribution on different atoms of morphine, along with that of Leu⁵- and Met⁵-enkephalins using CNDO/2 method is also reported. The similarity in charge distribution on some of the sites of these molecules is indicative of the possible interactions at the same receptor site. It is surmised that the recognition and interaction of active sites with the receptor must be dynamical in nature and for this the modes involving the active sites should play an important role. It is found that the binding to receptors is not static, but a dynamic process. <br/> <br/>Page(s): 173-181 http://nopr.niscair.res.in/handle/123456789/3277 Title: Effect of denaturants on the structure and activity of 3-hydroxybenzoate-6-hydroxylase <br/> <br/>Authors: Sumathi, S; Dasgupta, Dipak <br/> <br/>Abstract: The effect of denaturants such as urea, sodium dodecylsulphate (SDS), guanidinium hydrochloride (Gu.HCl) on the structure of enzyme 3-hydroxybenzoate-6-hydroxylase was studied using intrinsic fluorescence and far and near-UV-CD spectroscopic techniques. Also, activity profiles of the enzyme, as a function of increasing concentrations of denaturants were studied. The far-UV CD spectrum of the enzyme did not show appreciable alterations in the presence of urea, SDS or Gu.HCl, thereby suggesting that the protein does not undergo gross conformational changes in its -helical secondary structure. The treatment of enzyme with 2 M urea resulted in almost complete loss of catalytic activity, accompanied by the reduction of emission fluorescence of enzyme. Similarly, treatment with 0.01% SDS also caused almost complete loss of activity and quenching of enzyme fluorescence as well as a red shift in the emission peak. In addition, reduction in the intensity of near-UV-CD spectrum, especially at 280 nm was observed. About 70% of the activity was lost by treatment with 20 mM Gu.HCl, accompanied by quenching of intrinsic fluorescence of the enzyme. The change in intrinsic fluorescence of the enzyme in the presence of 5 mM-100 mM Gu.HCl could be correlated to progressive loss of catalytic activity. Thus, intrinsic fluorescence (due to tryptophan residues) could be used as an effective probe to provide an insight into the relation between the activity and subtle conformational changes of the enzyme. The results suggested that denaturants caused very slight conformational changes in the enzyme that perturbed the microenvironment of aromatic amino acid residues such as tryptophan accompanied by reduction or loss of catalytic activity. <br/> <br/>Page(s): 148-153 http://nopr.niscair.res.in/handle/123456789/3276 Title: Biophysical studies on the liposome-albumin system <br/> <br/>Authors: Al-Ayed, Mohammed S <br/> <br/>Abstract: The potential use of liposomes as a delivery system is still limited by the poor understanding of their interaction mechanisms with biological media. In the present work, interaction between bovine albumin (BA) and liposomes was studied using phase transition and dielectric measurements as well as solubilization process using non-ionic detergent octylglucoside (OG). After liposomes were incubated with diluted and concentrated BA, phase transition, characterizing the liposome membrane exhibited a shift towards higher temperatures, together with initiation of multiple phase transitions. The relaxation time of liposome membrane molecules also increased in a concentration-dependent manner. The solubilization profiles of incubated samples also showed remarkable changes, especially in beginning of solubilization stages. Moreover, amount of detergent needed to completely solubilize membrane was also increased. It was concluded that BA significantly altered the physical state of liposome membrane, which may be attributed to BA interaction with liposomes surface and/or by its incorporation within the bilayer membrane. <br/> <br/>Page(s): 186-189