Vibrational dynamics and heat capacity of polyglycine I

Earlier works on polyglycine I suffer from several infirmities, such as the dynamic methylene group being replaced by a mass unit and the use of poorly resolved inelastic neutron spectra, which have resulted in wrong assignments and imprecise profile of dispersion curves. In addition, the density-of-states and heat capacity variation as a function of temperature are being reported for the first time. The heat capacity is in good agreement with the measurements reported earlier by Roles and Wunderlich within a certain range (230-350 K). Deviations set in beyond this could be due to the presence of two crystalline states (I and II) in the sample used for the heat capacity measurements.     

Biodegradation of 4-aminobenzenesulphonate by a newly isolated bacterial strain PNS-1

A bacterial strain PNS-1, isolated from activated sludge derived from a domestic wastewater treatment unit, could utilize 4-aminobenzenesulphonate (4-ABS) as a sole organic carbon and energy source under aerobic conditions. Degradation rate varied with the initial concentration of 4-ABS and maximum specific substrate removal rate was observed at 400mg 4-ABS l^–1 (2.3mM). Average biomass yield was 0.31mg/mg 4-ABS degraded. Biokinetic parameters for the degradation, determined using the Haldane relationship, were 0.26h^–1 (_max), 6mg\,l^–1 (K_S) and 4020mg\,l^–1 (K_i). Strain PNS-1 could not utilize other isomers of benzenesulphonate and 5-sulphosalicylate as growth substrates whereas protocatechuate, pyrocatechuate and p-hydroxybenzoate could be degraded. In mixed substrate batch cultivations, where 4-ABS was one of the component, protocatechuate and 4-ABS were simultaneously utilized. Presence of 2- or 3-ABS decreased the growth and substrate degradation rates of 4-ABS. With 4-ABS and pyrocatechuate, although a lag phase was observed prior to pyrocatechuate degradation, a diauxic growth pattern was not seen.     

Identification of the fibroblast growth factor receptor in human vascular endothelial cells

The fibroblast growth factor (FGF) receptor of human umbilical vein-derived endothelial (HUE) cells has been identified by affinity labeling. It has an apparent molecular weight of 130,000. It binds both basic and acidic FGF, but not with epidermal growth factor, insulin, or transferrin. The lectin concanavalin-A does not inhibit the binding of ¹²⁵l-bFGF to HUE cell-surface receptors, whereas it inhibits bFGF binding to BHK-21 cell-surface FGF receptor. This suggests that both types of receptors may differ in their degree of glycosylation. In contrast to other cell types, heparin only slightly inhibits the binding of basic FGF to its receptor. Protamine sulfate, which is anti-angiogenic in vivo, and suramin, a drug used in the therapy of trypanosomiasis and onchocerciasis, also inhibit the binding of basic FGF to the receptor.     

In vitro propagation,clonal fidelity and phytochemical analysis of <Emphasis Type="Italic">Rhodiola imbricata</Emphasis> Edgew: a rare trans-Himalayan medicinal plant

The present study focuses on development of a micropropagation protocol for true to type plants of Rhodiola imbricata, an endangered medicinal plant found in trans-Himalayan Leh-Ladakh region of India. It also aims at analyzing the pharmaceutically important secondary metabolites and antioxidant potential of in vitro and in vivo plants. Various cytokinins and auxins were tested for shoot proliferation and in vitro rooting of the microshoots, respectively. Random primers were used for checking genetic uniformity at different stages of micropropagation. Pharmaceutically important secondary metabolites of R. imbricata such as Rosavin, total polyphenols and free radical scavenging activity were analyzed by HPLC. Among different cytokinins used, BAP (5 µM) and TDZ (1 µM) were found to perform better in terms of shoot proliferation, shoot length and number of leaves as compared to other concentrations. For rooting of microshoots, a lower concentration of NAA (0.5 µM) yielded more efficient rooting of micro shoots (17.33 roots per micro shoot). In vitro rooted microshoots were hardened and showed 60% survival rate. The content of gallic acid, chlorogenic acid and 4-hydroxybenzoic acid was higher in the in vivo plant. The amount of ferulic acid was higher in the in vitro raised plant when compared to field grown plant. Furthermore, caffeic acid and p-coumaric acid were higher in the in vitro raised plants as compared to field grown plants. This work will facilitate in conservation of this endangered herb and provide necessary plant materials for various biotechnological and pharmaceutical applications.     

Evaluation of novel TGR5 agonist in combination with Sitagliptin for possible treatment of type 2 diabetes

TGR5 is a member of G protein-coupled receptor (GPCR) superfamily, a promising molecular target for metabolic diseases. Activation of TGR5 promotes secretion of glucagon-like peptide-1 (GLP-1), which activates insulin secretion. A series of 2-thio-imidazole derivatives have been identified as novel, potent and orally efficacious TGR5 agonists. Compound 4d, a novel TGR5 agonist, in combination with Sitagliptin, a DPP-4 inhibitor, has demonstrated an adequate GLP-1 secretion and glucose lowering effect in animal models, suggesting a potential clinical option in treatment of type-2 diabetes.     

Solvent sensitivity of protein aggregation in Cu,Zn superoxide dismutase: a molecular dynamics simulation study

Misfolding and aggregation of Cu, Zn Superoxide Dismutase (SOD1) is often found in amyotrophic lateral sclerosis (ALS) patients. The central apo SOD1 barrel was involved in protein maturation and pathological aggregation in ALS. In this work, we employed atomistic molecular dynamics (MD) simulations to study the conformational dynamics of SOD1^barrel monomer in different concentrations of trifluoroethanol (TFE). We find concentration dependence unusual structural and dynamical features, characterized by the local unfolding of SOD1^barrel. This partially unfolded structure is characterized by the exposure of hydrophobic core, is highly dynamic in nature, and is the precursor of aggregation seen in SOD1^barrel. Our computational studies supports the hypothesis of the formation of aggregation ‘building blocks’ by means of local unfolding of apo monomer as the mechanism of SOD1 fibrillar aggregation. The non-monotonic TFE concentration dependence of protein conformational changes was explored through simulation studies. Our results suggest that altered protein conformation and dynamics within its structure may underlie the aggregation of SOD1 in ALS.     

Elucidation of stable intermediates in urea-induced unfolding pathway of human carbonic anhydrase IX

Human carbonic anhydrase IX (CAIX) has evolved as a promising biomarker for cancer prognosis, due to its overexpression in various cancers and restricted expression in normal tissue. However, limited information is available on its biophysical behavior. The unfolding of CAIX in aqueous urea solution was studied using all-atom molecular dynamics simulation approach. The results of this study revealed a stable intermediate state along the unfolding pathway of CAIX. At intermediate concentrations of urea (2.0–4.0 M), the protein displays a native-like structure with a large population of its secondary structure and hydrophobic contacts remaining intact in addition to small confined overall motions. Beyond 4.0 M urea, the unfolding is more gradual and at 8.0 M urea the structure is largely collapsed due to the solvent effect. The hydrophobic contact analysis suggests that the contact in terminal α-helices is separated initially which propagates in the loss of contacts from centrally located β-sheets. The reduction of 60–65% tertiary contacts in 7.0–8.0 M urea suggested the presence of residual structure in unfolded state and is confirmed with structural snap shot. Free energy landscape analysis suggested that unfolding of CAIX exists through the different intermediate states.     

Saccharomyces cerevisiae and Oenococcus oeni immobilized in different layers of a cellulose/starch gel composite for simultaneous alcoholic and malolactic wine fermentations

The production of a two-layer composite biocatalyst for immobilization of two different microorganisms for simultaneous alcoholic and malolactic fermentation (MLF) of wine in the same bioreactor is reported. The biocatalyst consisted of a tubular delignified cellulosic material (DCM) with entrapped Oenococcus oeni cells, covered with starch gel containing the alcohol resistant and cryotolerant strain Saccharomyces cerevisiae AXAZ-1. The biocatalyst was found effective for simultaneous low temperature alcoholic fermentation resulting to conversion of malic acid to lactic acid in 5 days at 10 °C. Improvement of wine quality compared with wine fermented with S. cerevisiae AXAZ-1 immobilized on DCM was attributed to MLF as well as to increased ester formation and lower higher alcohols produced at low fermentation temperatures (10 °C) as shown by GC and headspace SPME GC/MS analysis. Scanning electron microscopy showed that the preparation of a three-layer composite biocatalyst is also possible. The significance of such composite biocatalysts is the feasibility of two or three bioprocesses in the same bioreactor, thus reducing production cost in the food industry     

195 In silico study on HIV-PRIs substructures to terminate proteolytic activity in HTLV

Human T-lymphotropic virus (HTLV) is RNA retrovirus, which causes CD3?+?and CD4?+?T-cell type leukemia and demyelinating diseases, like tropical spastic myelopathy. The replicative stage of the virus is one of the critical stages for the development of the disease. At present, there are no approved therapeutic agents targeting HTLV. The HTLV mechanism of malignant cell growth in adult T-cell leukemia (ATL)/lymphoma, and the HTLV-PR has been an attractive target for anticancer drug design. In comparison with other retroviruses, HTLV also encodes protease (PR) enzyme which is essential for maturation. Both the HIV and HTLV proteases show high structural similarity but known inhibitors of HIV-PR are not able to inhibit the HTLV-PR, while comparing the binding pocket of both proteases, MET37 of HTLV shows repulsive role with known HIV inhibitors. Functional analysis of M37A mutation clearly shows that MET37 is highly important for the protease function. Available inhibitors were tested against the HTLV-PR binding pocket and failed to interact with MET37. Screening of similar libraries of known compounds provides better interactions with MET37 and further validation with in vivo and in vitro studies on these screened compounds will provide more strength in discovering potent inhibitor for HTLV-PR.