Initiation Reactions

Bài giảng này trình bày các nội dung liên quan đến phụ gia chống oxi hóa. Các nội dung được trình bày trong chương này gồm có: Types of Rancidity, Initiation Reactions, Propagation Reactions (Primary Reactions), Termination Reactions, Definitions of Antioxidants and Antioxidant Types,...và các nội dung liên quan khác.

29p namthangtinhlang_04 15-11-2015 113 28   Download

Objectives of thesis: Study on phenol treatment in water by ozonation process combined with catalysts. An empirical kinetic model and one quadratic regression equations were built based on experimental data for destroying phenol by heterogeneous catalytic ozonation process with response variables (initial pH, ozone concentration, catalyst concentration and reaction time). Application of phenol treatment in coking wastewater.

29p xacxuoc4321 08-07-2019 22 4   Download

Cannabinoid receptors and their endogenous ligands, the endocannabinoids, have been detected in several blood immune cells, including monocytes/macrophages, basophils and lymphocytes. However, their presence in dendritic cells, which play a key role in the initiation and development of the immune response, has never been investigated.

8p system191 01-06-2013 34 4   Download

The goal of this study was to determine the effects of a putative specific cytosolic phospholipase A2 inhibitor, arachidonyl trifluoromethyl ketone (AACOCF3), on arachidonic acid (AA) release and lipid mediator biosynthesis by ionophore-stimulated human neutrophils. Initial studies indicated that AACOCF3 at concentrations 0–10 lM did not affect AA release from neutrophils. In contrast, AACOCF3 potently inhibited leukotriene B4 formation by ionophore-stimulated neutrophils (IC50  2.5 lM).

11p system191 01-06-2013 48 4   Download

Recent years have witnessed high levels of activity in identifying enzyme systems that catalyse H-transfer by quantum tunneling. Rather than being restricted to a small number of specific enzymes as perceived initially, it has now become an accepted mechanism for H-transfer in a growing number of enzymes. Furthermore, H-tunneling is driven by the thermally induced dynamics of the enzyme. In some of those enzymes that break stable C–H bonds the reaction proceeds purely by quantum tunneling, without the need to partially ascend the barrier.

7p system191 01-06-2013 41 3   Download

A gene having high sequence homology (45–49%) with the glycerol-1-phosphate dehydrogenase gene from Methanobacterium thermoautotrophicum was cloned from the aerobic hyperthermophilic archaeon Aeropyrum pernix K1 (JCM 9820). This gene expressed in Escherichia coli with the pET vector system consists of 1113 nucleotides with an ATG initiation codon and a TAG termination codon. The molecular mass of the purified enzyme was estimated to be 38 kDa by SDS/PAGE and 72.4 kDa by gel column chromatography, indicating presence as a dimer....

8p research12 01-06-2013 31 4   Download

To identify and gain a better understanding of the cadherin-like receptor-binding site onBacillus thuringiensisCry toxins, it is advantageous to use Cry1Aa toxin, because its 3D structure is known. Therefore, Cry1Aa toxin was used to examine the locations of cadherin-like protein-binding sites. Initial experiments examining the binding compatibility for Cry1Aa toxin of partial fragments of recombinant proteins of a 175 kDa cadherin-like protein from Bombyx mori(BtR175) and another putative receptor for Cry1Aa toxin, aminopeptidase N1, fromBo. ...

14p research12 29-04-2013 45 3   Download

Biosynthesis ofmucin-typeO-glycans is initiated by a family of UDP-GalNAc:polypeptide N-acetylgalactosaminyl-transferases, which contain several conserved cysteine resi-dues among the isozymes. We found that a cysteine-specific reagent, p-chloromercuriphenylsulfonic acid (PCMPS), irreversibly inhibited one of the isozymes (GalNAc-T1). Presence of either UDP-GalNAc or UDP during PCMPS treatment protected GalNAc-T1 from inactivation, to the same extent.

9p research12 23-04-2013 39 3   Download

The use ofBacillus amyloliquefaciensfor enzyme production and its exceptional highprotein export capacity initiated this study where the presence and function of multiple type I signal peptidase isoforms was investigated. In addition to type I signal peptidases SipS(ba) [Meijer,W.J.J., de Jong,A., Bea, G., Wisman, A., Tjalsma, H., Venema, G., Bron, S. & van Dijl, J.M. (1995)Mol. Microbiol.17, 621±631] and SipT(ba) [Hoang, V. & Hofemeister, J. (1995) Biochim. Biophys.

12p research12 23-04-2013 37 4   Download

The matrix metalloproteinase (MMP) family degrades the extracellular matrix. One member of this family, MMP-1, initiates the breakdown of interstitial collagens. The expression ofMMP-1 is controlled by themitogen activated protein kinase (MAPK) pathway(s) via the activity of acti-vator protein-1 (AP-1) and polyoma enhancing activity-3/ E26 virus (PEA3/ETS) transcription factors through con-sensus binding sites present in the promoter.

10p tumor12 20-04-2013 33 3   Download

Mammalian translation initiation factor 3 (eIF3) is a multisubunit complex containingat least 12 subunitswithan apparent aggregate mass of
700 kDa.eIF3 binds to the 40S ribosomal subunit, promotes the binding of methionyl-tRNA i and mRNA, and interacts with several other initi-ation factors to form the 40S initiation complex.Human cDNAs encoding 11 of the 12 subunits have been isolated previously; here we report the cloning and characterization of a twelfth subunit, a 28-kDa protein named eIF3k.Evi-dence that eIF3k is present in the eIF3 complex was obtained....

7p tumor12 20-04-2013 35 3   Download

It was shown previously [Riedinger, H. J., van Betteraey-Nikoleit, M & Probst, H. (2002)Eur. J. Biochem.269, 2383–2393] that initiation ofin vivo SV40 DNA replication is reversibly suppressed by hypoxia in a state where viral minichromosomes exhibit a nearly complete set of repli-cation proteins. Reoxygenation triggers fast completion and post-translational modifications.

11p tumor12 20-04-2013 31 2   Download

A number of proteins related to the homotetrameric trans-port protein transthyretin (TTR) forms a highly conserved protein family, whichwe present in an integrated analysis of data from different sources combined with an initial bio-chemical characterization.Homologues of the transthyretin-relatedprotein (TRP) canbe found inawide rangeof species including bacteria, plants and animals, whereas transthyre-tinshave so faronlybeen identified invertebrates.

15p tumor12 20-04-2013 49 3   Download

The capacity of dendritic cells to initiate T cell responses is related to their ability to redistribute MHC class II mole-cules from the intracellular MHC class II compartments to the cell surface. This redistribution occurs during dendritic cell development as they are converted from an antigen capturing, immature dendritic cell into an MHC class II-peptide presenting mature dendritic cell. During this matu-ration, antigen uptake and processing are down-regulated and peptide-loaded class II complexes become expressed in a stable manner on the cell surface. ...

9p fptmusic 16-04-2013 47 3   Download

Caspases are a conserved family of cysteine proteases. They play diverse roles in inflammatory responses and apoptotic pathways. Among the casp-ases is a subgroup whose primary function is to initiate apoptosis. Within their long prodomains, caspases-2, -9 and -12 contain a caspase activation and recruitment domain while caspases-8 and -10 bear death effector domains.

18p fptmusic 12-04-2013 43 2   Download

We examined whether the fast release of replicon initiation after sudden O2 recovery of hypoxically incubated mammalian cells depends on kinase activity of Cdk2. We used a system based on starved⁄refed T24 cells elab-orated previously for such investigations [van Betteraey-Nikoleit M, Eisele KH, Stabenow D & Probst H (2003)Eur J Biochem270, 3880–3890].

12p fptmusic 12-04-2013 45 2   Download

Investigations of protein–solute interactions typically show that osmolytes favor native conformations. In this study, the effects of representative compatible and counteracting osmolytes on the reactivationof lactate dehydrogenase from two different conformational states were explored. Contrary to expectations, proline and trimethylamine oxide inhibited both the initial time course and the extent of reactivation of lactate dehydrogenase from bovine heart following dena-turation in guanidine hydrochloride, as well as following inactivation at pH 2.3.

12p fptmusic 12-04-2013 42 2   Download

In our attempt to obtain further information on the replication mechanism of the hepatitis C virus (HCV), we have studied the role of sequences at the 3¢-end of HCV minus-strand RNA in the initiation of synthesis of the viral genome by viral RNA-dependent RNA polymerase (RdRp). In this report, we investigated the template and binding properties of mutated and deleted RNA fragments of the 3¢-end of the minus-strand HCV RNA in the presence of viral polymerase.

15p fptmusic 11-04-2013 54 3   Download

Peripheral nerve injury is normally followed by a robust regenerative response. Here we describe the early changes associated with injury from the initial rise in intracellular calcium and the subsequent activation of transcription factors and cytokines leading to an inflammatory reaction, and the expression of growth factors, cytokines, neuropeptides, and other secreted molecules involved in cell-to-cell communication promoting regen-eration and neurite outgrowth.

11p awards 06-04-2013 39 3   Download

Cyclobutane-type pyrimidine dimers generated by ultraviolet irradiation of DNA can be cleaved by DNA photolyase. The enzyme-catalysed reaction is believed to be initiated by the light-induced transfer of an electron from the anionic FADH ) chromophore of the enzyme to the pyrimidine dimer. In this contribution, first infrared experiments using a novel E109A mutant ofEscherichia coliDNA photolyase, which is catalytically active but unable to bind the second cofactor methenyltetrahydrofolate, are described....

0p awards 06-04-2013 29 2   Download