Chain of chemical reactions

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 31 2   Download

Genomicfattyacid elongation 1 (FAE1) clones from high erucic acid (HEA)Brassica napus, Brassica rapaandBras-sicaoleracea, and lowerucicacid (LEA)B. napuscv.Westar, were amplifiedbyPCRand expressed inyeast cells under the control of the strong galactose-inducible promoter. As expected, yeast cells expressing theFAE1genes from HEA Brassicaspp. synthesized very long chain monounsaturated fatty acids that are not normally found in yeast, while fatty acid profiles of yeast cells expressing theFAE1gene from LEA B. napuswere identical to control yeast samples....

7p tumor12 22-04-2013 41 2   Download

The exopolysaccharide produced byStreptococcus thermo-philus8S in reconstituted skimmed milk is a heteropolysac-charide containing D-galactose, D-glucose, D-ribose, and N-acetyl-D-galactosamine in a molar ratio of 2:1:1:1. Furthermore, the polysaccharide contains one equivalent of a novel open chain nononic acid constituent, 3,9-dideoxy-D-threo-D-altro-nononic acid, ether-linked viaC-2 toC-6 of an additionalD-glucose per repeating unit.

9p tumor12 22-04-2013 32 2   Download

Keyhole limpet (Megathura crenulata) hemocyanin (KLH), an extracellular respiratory protein, is widely used as hapten carrier and immune stimulant. Although it is generally accepted that the sugar constituents of this glycoprotein are likely to be implicated in the antigenicity and biomedical properties of KLH, knowledge of its carbohydrate structure is still limited. Therefore, we have investigated the N-linked oligosaccharides of KLH. Glycan chains were enzymati-cally liberated from tryptic glycopeptides, pyridylaminated and separated by two-dimensional HPLC....

15p tumor12 22-04-2013 33 2   Download

The role of the negative charge of the E139 side-chain of AnabaenaFerredoxin-NADP + reductase (FNR) in steering appropriate docking with its substrates ferredoxin, flavo-doxin and NADP + /H, that leads to efficient electron transfer (ET) is analysed by characterization of several E139 FNRmutants. Replacement of E139 affects the interaction with the different FNRsubstrates in very different ways.

10p tumor12 22-04-2013 37 2   Download

Cytochrome P450BM3is a self-sufficient fatty acid mono-oxygenase consisting of a diflavin (FAD/FMN) reductase domain and a heme domain fused together in a single polypeptide chain. The multidomain structure makes it an ideal model system for studying the mechanism of electron transfer and for understanding P450 systems in general. Here we report the redox properties of the cyto-chrome P450BM3 wild-type holoenzyme, and its isolated FADreductase andP450 heme domains, when immobilized in a didodecyldimethylammonium bromide film cast on an edge-plane graphite electrode....

7p tumor12 20-04-2013 46 3   Download

Thehemolysateofthe AntarcticteleostGobionotothen gibberifrons(family Nototheniidae) contains two hemoglo-bins (Hb 1 andHb 2). The concentration of Hb 2 (15–20% of the total hemoglobin content) is higher than that found in most cold-adapted Notothenioidei. Unlike the other Antarctic species so far examined having two hemoglobins, Hb 1 and Hb 2 do not have globin chains in common. Therefore this hemoglobin system is made of four globins (two a-and twob-chains). The complete amino-acid sequence of the two hemoglobins (Hb 1,a 1 2b 1 2 ;Hb 2,a 2 b 2 2 ) has been established. ...

7p tumor12 20-04-2013 27 4   Download

As one of the most important families of non-natural poly-mers with the propensity to form well-defined secondary structures, theb-peptides are attracting increasing attention. The compounds incorporatingb-amino acid residues have found various applications in medicinal chemistry and biochemistry.The conformational pool ofb-peptides com-prises several periodic folded conformations, which can be classified as helices, and nonpolar and polar strands.The latter two are prone to form pleated sheets.

10p tumor12 20-04-2013 30 4   Download

The structure of the antigenic O-chain polysaccharide of Flavobacterium columnareATCC 43622, a Gram-negative bacteriumthat causes columnaris disease inwarmwater fish, was determined by high-field 1D and 2D NMR techniques, MS, and chemical analyses. The O-chain was shown to be an unbranched linear polymer of a trisaccharide repeat-ing unit composed of 2-acetamido-2-deoxy-D-glucuronic acid (D-GlcNAcA),

7p tumor12 20-04-2013 38 3   Download

Acomprehensive, structural and functional, insilicoanalysis of the medium-chain dehydrogenase/reductase (MDR) superfamily, including 583 proteins, was carried out by use of extensive database mining and theBLASTPprogram in an iterative manner to identify all known members of the superfamily. Based on phylogenetic, sequence, and func-tional similarities, the protein members of the MDR super-family were classified into three different taxonomic categories: (a) subfamilies, consisting of a closed group containing a set of ideally orthologous proteins that perform the same function;...

26p tumor12 20-04-2013 35 5   Download

Engineered yeast cells efficiently convert ergosta-5-eneol to pregnenolone and progesterone provided that endogenous pregnenolone acetylase activity is disrupted and that heterologous sterolD7-reductase, cytochrome P450 side chain cleavage (CYP11A1) and 3b hydroxysteroid dehydrogenase/isomerase (3b-HSD) activities are present. CYP11A1activity requires the expressionof themammalian NADPH-adrenodoxin reductase (Adrp) and adrenodoxin (Adxp) proteins as electron carriers.

13p tumor12 20-04-2013 28 2   Download

Mitochondrial cytochromecoxidase is a key protonmotive component of the respiratory chain. Mutations in the mito-chondrially-encoded subunits of the complex have been reported in associationwith a range of diseases. In this work we used yeast and bacterial mutants to assess the effect of humanmutations insubunit 1 (L196I) andsubunit 3 (G78S, A200T,DF94–F98, F251L and W249Stop).

9p tumor12 20-04-2013 34 1   Download

The X-ray structure of mistletoe lectin I (MLI), a type-II ribosome-inactivatingprotein (RIP), cocrystallized with galactose is described. The model was refined at 3.0 A ˚ resolution to an R-factor of 19.9% using21 899 reflections, with Rfree 24.0%. MLI forms a homodimer (A–B)2in the crystal, as it does in solution at high concentration. The dimer is formed through contacts between the N-terminal domains of two B-chains involvingweak polar and non-polar interactions.

11p fptmusic 16-04-2013 43 3   Download

The antigenicity ofCandida lusitaniaecells was found to be thesameasthatof Candida albicansserotype A cells, i.e. both cell wall mannans react with factors 1, 4, 5, and 6 sera of Candida Check. However, the structure of the mannan of C. lusitaniaewas significantly different from that of C. albicansserotype A, and we found novelb-1,2 linkages among the side-chainoligosaccharides,Manb1fi2Manb1fi 2Mana1fi2Mana1fi2Man (LM5), and Manb1fi2Man-b1fi2Manb1fi2Mana1fi2Mana1fi2Man (LM6).

11p fptmusic 16-04-2013 55 6   Download

Catalytic antibodies capable of digesting crucial proteins of pathogenic bac-teria have long been sought for potential therapeutic use. Helicobacter pyloriurease plays a crucial role for the survival of this bacterium in the highly acidic conditions of human stomach. The HpU-9 monoclonal anti-body (mAb) raised againstH. pyloriurease recognized thea-subunit of the urease, but only slightly recognized theb-subunit. However, when isolated both the light and the heavy chains of this antibody were mostly bound to the b-subunit....

9p fptmusic 11-04-2013 45 3   Download

The membrane-tethered mucins are cell surface-associated dimeric or multi-meric molecules with extracellular, transmembrane and cytoplasmic por-tions, that arise from cleavage of the primary polypeptide chain. Following the first cleavage, which may be cotranslational, the subunits remain closely associated through undefined noncovalent interactions.

11p awards 06-04-2013 41 3   Download

Phosphorylase kinase (PhK) is a large hexadecameric enzyme consisting of four copies of four subunits: (abcd)4. An intrinsic calmodulin (CaM, the d subunit) binds directly to the cprotein kinase chain. The interaction site of CaM onchas been localized to a C-terminal extension of the kinase domain. Two 25-mer peptides derived from this region, PhK5 and PhK13, were identified previously as potential CaM-binding sites.

12p awards 06-04-2013 37 4   Download

Endo-b-mannosidase is an endoglycosidase that hydrolyzes only the Manb1-4GlcNAc linkage of the core region of N-linked sugar chains. Recently, endo-b-mannosidase was purified to homogeneity from Lilium longiflorum (Lily) flowers, its corresponding gene was cloned and import-ant catalytic amino acid residues were identified [Ishimizu T., Sasaki A., Okutani S., Maeda M., Yamagishi M. & Hase S. (2004)J. Biol. Chem. 279, 38555–38562].

0p awards 06-04-2013 32 3   Download

Heme oxygenase (HO) catalyzes the oxidative degradation of heme utilizing molecular oxygen and reducing equiva-lents. In photosynthetic organisms, HO functions in the biosynthesis of such open-chain tetrapyrroles as phyto-chromobilin and phycobilins, which are involved in the sig-nal transduction for light responses and light harvesting for photosynthesis, respectively.

9p awards 05-04-2013 31 3   Download

The SUMO proteins are a class of small ubiquitin-like modifiers. SUMO is attached to a specific lysine side chain on the target protein via an isopeptide bond with its C-terminal glycine.Thereareat least fourSUMOproteins in humans, which are involved in protein trafficking and tar- geting. A truncated human SUMO-2 protein that contains residues 9–93 was expressed inEscherichia coliand crystal- lized in two different unit cells, with dimensions of a ¼b¼ 75.25 A ˚ ,c¼29.17 A ˚ and a¼b¼74.96 A ˚ ,c¼33.23 A ˚ , both belonging to the rhombohedral space groupR3. They diffractedX-rays to1.

9p awards 05-04-2013 39 4   Download