Modes of action

The design of solar cars has historically been dominated by highly technical and performance-based criteria. This has limited the general acceptance of solar cars as a viable mode of transport in both the public eye and the automotive industry.

189p runthenight04 02-02-2023 8 3   Download

Agrobacterium tumefaciens is a Gram-negative, phytopathogenic bacterium and is characterized by an unique mode of action on dicotyledonous plants: it is able to genetically modify the host, and because of this feature, it is used as a tool for transgenic plants. Many experiments have demonstrated that lipopolysaccharides (LPSs) play an important role for the disease development, as they are involved in the adhesion process of the bacterium on the plant cell wall.

4p system191 01-06-2013 32 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 45 6   Download

A100-kDa proteinwith endoglucanase activitywas purified from Triton X-100 extract of cells of the thermoacidophilic Gram-positive bacterium Alicyclobacillus acidocaldarius. The enzyme exhibited activity towards carboxy methyl cel-lulose and oat spelt xylan with pH and temperature optima of 4 and 80
C, respectively. Cloning and nucleotide sequence analysis of the corresponding gene (celB) revealed an ORF encoding a preprotein of 959 amino acids which is consistent with an extracellular localization.

10p tumor12 20-04-2013 33 2   Download

Sequence analysis of aPaenibacillussp. BP-23 recombinant clone coding for a previously described endoglucanase revealed the presence of an additional truncated ORF with homology to family 48 glycosyl hydrolases. The corres-ponding 3509-bp DNA fragment was isolated after gene walking and cloned inEscherichia coliXl1-Blue for expres-sion and purification. The encoded enzyme, a cellulase of 1091 amino acids with a deduced molecular mass of 118 kDa and a pI of 4.

7p fptmusic 16-04-2013 50 3   Download

An intracellular pectinolytic enzyme, PelB (TM0437), from the hyperther-mophilic bacteriumThermotoga maritimawas functionally produced in Escherichia coliand purified to homogeneity. PelB belongs to family 28 of the glycoside hydrolases, consisting of pectin-hydrolysing enzymes. As one of the few bacterial exopolygalacturonases, it is able to remove monogalac-turonate units from the nonreducing end of polygalacturonate.

10p fptmusic 12-04-2013 27 2   Download

We have previously reported that sulfoquinovosylmonoacylglycerol (SQMG) is a potent inhibitor of mammalian DNA polymerases. DNA polymeraseb(pol b) is one of the most important enzymes protecting the cell against DNA damage by base excision repair. In this study, we charac-terized the inhibitory action of SQMG against rat pol b. SQMG competed with both the substrate and the template-primer for binding to polb.

13p fptmusic 11-04-2013 40 1   Download

The twin-arginine translocation (Tat) system transports folded proteins across the bacterial plasma membrane. Three subunits, TatA, B and C, are known to be involved but their modes of action are poorly understood, as are the inter-subunit interactions occurring within Tat complexes. We have generated mutations in the single transmembrane (TM) spans of TatA and TatB, with the aim of generating structural distortions.

15p awards 06-04-2013 33 2   Download

Juvenile hormones (JHs) of insects are sesquiterpenoids that regulate a great diversity of processes in development and reproduction. As yet the molecular modes of action of JH are poorly understood. TheMethoprene-tolerant (Met) gene of Drosophila melanogasterhas been found to be responsible for resistance to a JH analogue (JHA) insecticide, methoprene. Previous studies onMethave implicated its involvement in JH signaling, although direct evidence is lacking.

0p awards 05-04-2013 33 1   Download

Propionate is used to protect bread and animal feed from moulds. The mode of action of this short-chain fatty acid was studied usingAspergillus nidulansas a model organism. The filamentous fungus is able to grow slowly on propio-nate, which is oxidized to acetyl-CoA via propionyl-CoA, methylcitrate and pyruvate. Propionate inhibits growth of A. nidulanson glucose but not on acetate; the latter was shown to inhibit propionate oxidation.

15p awards 05-04-2013 45 3   Download

As an essential element, selenium is present in enzymes from several families, including glutathione peroxidases, and is thought to exert anticarcinogenic properties. A remarkable feature of selenium consists of its ability to oxidize thiols under reducing conditions. Thus, one mode of action recently suggested is the oxidation of thiol groups of metal-lothionein, thereby providing zinc for essential reactions.

10p awards 05-04-2013 45 3   Download

GE23077, a novel microbial metabolite recently isolated from Actinomadurasp. culture media, is a potent and selective inhibitor of bacterial RNApolymerase (RNAP). It inhibitsGram-positive (Bacillus subtilis) andGram-negative (Escherichia coli)RNAPs with IC50 values (i.e. the concen-tration at which the enzyme activity is inhibited by 50%) in the 10 )8 Mrange, whereas it is not active onE. coliDNA polymerase or on eukaryotic (wheat germ) RNAP II (IC50 values10 )4 Min both cases).

0p awards 05-04-2013 56 2   Download

The GM2-activator protein (GM2AP) is an essential cofactor for the degradation of ganglioside GM2 by lyso-somal b-hexosaminidase A. It mediates the interaction between the water-soluble exohydrolase and its membrane-bound substrate at the lipid–water interphase. Inherited defects in the gene encoding this glycoprotein result ina fatal neurological storage disorder, the AB variant of GM2-gangliosidosis. To elucidate the mode of action of this gly-coprotein cofactor, we synthesized the two photoaffinity labels [ 14 C]C3 -TPD-GM2 and [ 14 C]C7 -TPD-GM2. ...

14p dell39 03-04-2013 61 4   Download

Model amphipathic peptides have been widely used as a tool to determine the structural and biological properties that control the interaction of pep-tides with membranes. Here, we have focused on the role of a central Pro in membrane-active peptides. To determine the role of Pro in structure, antibiotic activity, and interaction with phospholipids, we generated a ser-ies of model amphipathic a-helical peptides with different chain lengths and containing or lacking a single central Pro.

15p inspiron33 25-03-2013 39 3   Download

The mode of action of xylanase A from a phytopathogenic bacterium, Erwinia chrysanthemi, classified in glycoside hydrolase family 5, was investi-gated on xylooligosaccharides and polysaccharides using TLC, MALDI-TOF MS and enzyme treatment with exoglycosidases.

12p galaxyss3 21-03-2013 46 2   Download

Sphingolipid activator proteins (SAPs), GM2 activator protein (GM2AP) and saposins (Saps) A–D are small, enzymatically inactive glycoproteins of the lysosome. Despite of their sequence homology, these lipid-binding and -transfer proteins show different specificities and varying modes of action. Water-soluble SAPs facilitate the degradation of membrane-bound glyco-sphingolipids with short oligosaccharide chains by exohydrolases at the membrane–water interface.

16p galaxyss3 19-03-2013 31 3   Download

We present the design, synthesis, anti-HIV-1 and mode of action of neomy-cin and neamine conjugated at specific sites to arginine 6- and 9-mers d- and l-arginine peptides (APACs). The d-APACs inhibit the infectivity of X4 HIV-1 strains by one or two orders of magnitude more potently than their respective l-APACs.

14p media19 05-03-2013 36 2   Download

Geotrichumsp. M128 possesses two xyloglucan-specific glycoside hydrolases belonging to family 74, xyloglucan-specific endo-b-1,4-glucanase (XEG) and oligoxyloglucan reducing-end-specific cellobiohydrolase (OXG-RCBH). Despite their similar amino acid sequences (48% identity), their modes of action and substrate specificities are distinct.

7p vinaphone15 25-02-2013 35 3   Download

Staphylococcus aureushas one essential type I signal peptidase (SPase), SpsB, which has emerged as a potential target in the search for antibiotics with a new mode of action. In this framework, the biochemical properties of SpsB are described and compared with other previously characterized SPases.

13p viettel02 22-02-2013 37 3   Download

The enzymatic hydrolysis of cellulose encounters various limitations that are both substrate- and enzyme-related. Although the crystallinity of pure cellulosic Avicel plays a major role in determining the rate of hydrolysis by cellulases from Trichoderma reesei, we show that it stays constant during enzymatic conversion. The mode of action of cellulases was investigated by studying their kinetics on cellulose samples.

12p mobifone23 18-01-2013 48 5   Download