Enzymatic

The results of microbiological and toxicological tests have proved the safety of the bone-muscular cod waste (BMW). Waste (humerus with meat cuts) from cod cutting on fillets contains 18,95 % of a full-grade animal protein and insignificant amount of fat (0.15 %).

14p lucastanguyen 01-06-2020 20 2   Download

A pot culture experiment was conducted to study the effect of humic acid on soil microbial population and enzymatic activity in groundnut in an Alfisol at Main Agricultural Research Station, Dharwad.

5p gaocaolon5 14-06-2020 6 1   Download

With the aim to distinguish between local and global conformational changes induced by trifluoroethanol in RNase A, spectroscopic and activity measurements in combination with proteolysis by unspecific proteases have been exploited for probing structural transitions of RNase A as a function of trifluoroethanol concentration. At 30% (v/v) trifluoroethanol (pH 8.0; 25 °C), circular dichroism and fluorescence spectroscopy indicate a cooperative collapse of the tertiary structure of RNase A coinciding with the loss of its enzymatic activity....

7p system191 01-06-2013 49 3   Download

This review describes studies of particular enzymatically catalyzed reactions to investigate the possibility that catalysis is mediated by protein dynamics. That is, evolution has crafted the protein backbone of the enzyme to direct vibrations in such a fashion to speed reaction. The review presents the theoretical approach we have used to investigate this problem, but it is designed for the nonspecialist.

10p system191 01-06-2013 37 4   Download

An exo-1,3-b-glucanase has been isolated from cultural filtrate of Trichoderma viride AZ36. The N-terminal sequence of the purified enzyme (m ¼ 61 ^ 1 kDa) showed no significant homology to other known glucanases. The 1,3-b-glucanase displayed high activity against laminarins, curdlan, and 1,3-b-oligoglucosides, but acted slowly on 1,3-1,4-b-oligoglucosides. No significant activity was detected against high molecular mass 1,3-1,4-bglucans. The enzyme carried out hydrolysis with inversion of the anomeric configuration.

9p system191 01-06-2013 46 6   Download

The calcineurin (CaN) a and b catalytic subunit isoforms are coexpressed within almost all cell types. The enzymatic properties of CaN heterodimers comprised of the regulatory B subunit (CnB) with either the a or b catalytic subunit were compared using in vitro phosphatase assays. CaN containing the a isoform (CnAa) has lower Km and higher Vmax values than CaN containing the b isoform (CnAb) toward the PO4RII, PO4-DARPP-32(20–38) peptides, and p-nitrophenylphosphate (pNPP).

9p research12 01-06-2013 28 3   Download

This study investigated the enzymatic function of two putative plant GPXs, GPXle1 from Lycopersicon esculentum and GPXha2 from Helianthus annuus, which show sequence identities with the mammalian phospholipid hydroperoxide glutathione peroxidase (PHGPX). Both purified recombinant proteins expressed in Escherichia coli show PHGPX activity by reducing alkyl, fatty acid and phospholipid hydroperoxides but not hydrogen peroxide in the presence of glutathione.

7p research12 01-06-2013 37 4   Download

We previously demonstrated that the major ecto-nucleoside triphosphate phosphohydrolase in the chicken liver membranes is an ecto-ATP-diphosphohydrolase (ectoATPDase) [Caldwell, C., Davis, M.D. & Knowles, A.F. (1999) Arch. Biochem. Biophys. 362, 46–58]. Enzymatic properties of the liver membrane ecto-ATPDase are similar to those of the chicken oviduct ecto-ATPDase that we have previously purified and cloned. Using antibody developed against the latter, we have purified the chicken liver ecto-ATPDase to homogeneity. ...

10p research12 01-06-2013 40 5   Download

In order to study some of its enzymatic properties, phosphatidylinositol synthase 1 (AtPIS1) from the plant Arabidopsis thaliana was expressed in Escherichia coli, a host naturally devoid of phosphatidylinositol (PtdIns). In the context of the bacterial membrane and in addition to de novo synthesis, the plant enzyme is capable of catalysing the exchange of the inositol polar head for another inositol. Our data clearly show that the CDP-diacylglycerol-independent exchange reaction can occur using endogenous PtdIns molecular species or PtdIns molecular species from soybean added exogenously....

6p research12 01-06-2013 34 5   Download

Nuclear receptors (NRs) are ligand-regulated, DNA-binding transcription factors that function in the chromatin environment of the nucleus to alter the expression of subsets of hormone-responsive genes. It is clear that chromatin, rather than being a passive player, has a profound effect on both transcriptional repression and activation mediated by NRs.

9p research12 01-06-2013 32 2   Download

By replacing specific amino acids at positions 112, 147 and 152 of the human aldosterone synthase (CYP11B2) with the corresponding residues from human, mouse or rat 11b-hydroxylase (CYP11B1), we have been able to investigate whether these residues belong to structural determinants of individual enzymatic activities. When incubated with 11-deoxycorticosterone (DOC), the 11b-hydroxylation activity of the mutants was most effectively increased by combining D147E and I112P (sixfold increase).

10p research12 01-06-2013 37 4   Download

We have recently expressed in bacteria the enzymatically active reverse transcriptase (RT) of bovine leukemia virus (BLV) [Perach, M. & Hizi, A. (1999) Virology 259, 176–189]. In the present study, we have studied in vitro two features of the DNA polymerase activity of BLV RT, the processivity of DNA synthesis and the fidelity of DNA synthesis. These properties were compared with those of the well-studied RTs of human immunodeficiency virus type 1 (HIV-1) and murine leukaemia virus (MLV).

9p research12 01-06-2013 43 4   Download

The thermal stabilityofperoxidase fromleavesof theAfrican oil palm treeElaeis guineensis(AOPTP) at pH 3.0 was studied by differential scanning calorimetry (DSC), intrinsic fluorescence, CD and enzymatic assays.The spectral parameters asmonitoredby ellipticity changes in the far-UV CD spectrum of the enzyme as well as the increase in tryp-tophan intensity emission upon heating, together with changes in enzymatic activity with temperature were seen to be good complements to the highly sensitive but integral methodofDSC....

7p research12 29-04-2013 45 3   Download

Glutathione reductase (GR) recycles oxidized glutathione (GSSG) by converting it to the reduced form (GSH) using an NADPH as the electron source. The function of GR in the male genital tract of the rat was examined by meas-uring its enzymatic activity and examining the gene expression and localization of the protein.

9p research12 29-04-2013 49 3   Download

Theb1,3-glycosyltransferase enzymes identi®ed to date share several conserved regions and conserved cysteine res-idues, all being located in the putative catalytic domain. To investigate the importance of these motifs and cysteines for the enzymatic activity, 14 mutants of the murine b1,3-galactosyltransferase-I gene were constructed and expressed in Sf9 insect cells. Seven mutations abolished the galacto-syltransferase activity.

7p research12 29-04-2013 38 3   Download

Lamjapin,anoveltypeIribosome-inactivating protein, has been isolated from kelp (Laminaria japonicaA), a marine alga. This protein has been extensively purified through multiple chromatography columns. With a molecular mass of
36 kDa, lamjapin is slightly larger than the other known single-chain ribosome-inactivating proteins from the higher plants. Lamjapin can inhibit protein synthesis in rabbit reticulocyte lysate with an IC50 of 0.69 nM.

7p research12 23-04-2013 32 2   Download

It is scientifically and industrially important 1 to clarify the stabilizing mechanism of proteases in extraordinary envi-ronments. We used subtilisins ALPI and Sendai as models to study the mechanism. Subtilisin ALPI is extremely sensitive to highly alkaline conditions, even though the enzyme is produced by alkalophilicBacillus, whereas sub-tilisin Sendai from alkalophilic Bacillusis stable under conditions of high alkalinity.

9p research12 23-04-2013 45 1   Download

Reactionof certainpeptides andproteinswithsingletoxygen (generated by visible light in the presence of rose bengal dye) yields long-lived peptide and protein peroxides. Incubation of these peroxides with glyceraldehyde-3-phosphate dehy-drogenase, in the absence of addedmetal ions, results in loss of enzymatic activity. Comparative studies with a range of peroxides have shown that this inhibition is concentration, peroxide, and time dependent, with H2O2less ecient than some peptide peroxides.

10p research12 23-04-2013 39 4   Download

The mature cysteine protease from Dermatophgoides pteronyssinus, Der p 1, is a major house dust mite allergen. Its enzymatic activity has been shown to have pro-in¯am-matory e€ects that could alsonegatively in¯uence ecacy of allergen-speci®c immunotherapy. The aimof this study was to express recombinant pro-Der p 1 (rpro-Der p 1) in the yeastPichia pastorisand to study itsmaturation.

9p research12 23-04-2013 30 2   Download

We have previously identi®ed a DNA ligase (LigTk)froma hyperthermophilic archaeon,Thermococcus kodakaraensis KOD1. The enzyme is the only characterized ATP-depend-ent DNA ligase from a hyperthermophile, and allows the analysis of enzymatic DNA ligation reactions at tempera-tures above themeltingpoint of the substrates.Herewe have focused on the interactions of LigTkwith various DNA substrates, and its speci®cities toward metal cations.

7p research12 23-04-2013 34 2   Download