Antimicrobial activity

Marine fungi have become an important source of bioactive natural products. The present study was concerned with the screening of antimicrobial activity from 73 fungal strains isolated from various marine habitats collected from five different localities at the Son Tra Peninsula, Da Nang, Vietnam.

6p jangni 16-04-2018 0 0   Download

To elucidate the structural features of the mussel defensin MGD1 required for antimicrobial activity, we synthesized a series of peptides corresponding to the main known secon-dary structures of the molecule and evaluated their activity towards Gram-positive and Gram-negative bacteria, and filamentous fungi. We found that the nonapeptide corres-ponding to residues 25–33 of MGD1 (CGGWHRLRC) exhibited bacteriostatic activity once it was cyclized by a non-naturally occurring disulfide bridge.

9p fptmusic 16-04-2013 28 1   Download

Shiitake mushroom contains several therapeutic actions such as antioxidant and antimicrobial properties, carried by the diversity of its components. In the present work, extracts from shiitake mushroom were obtained using different extraction techniques: high-pressure operations and low-pressure methods. The high-pressure technique was applied to obtain shiitake extracts using pure CO2 and CO2 with co-solvent in pressures up to 30 MPa.

8p the_eye_1991 18-09-2012 40 5   Download

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài: " IL-4 and IL-13 exposure during mucociliary differentiation of bronchial epithelial cells increases antimicrobial activity and expression of antimicrobial peptides...

12p toshiba11 20-10-2011 17 2   Download

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Antimicrobial activity of spherical silver nanoparticles prepared using a biocompatible macromolecular capping agent: evidence for induction of a greatly prolonged bacterial lag phase

12p toshiba25 08-12-2011 25 2   Download

The natural antimicrobial cationic peptide protegrin-1 displays a broad spectrum of antimicrobial activity and rapidly kills pathogens by interacting with their cell membrane. We investigated the structure–activity relation-ships of three protegrin-1 analogues: IB-367 (RGGLCYCRGRFCVCVGR-NH2), BM-1 (RGLCYCRGRFCVCVG-NH2) and BM-2 (RGLCYRPRFV CVG-NH2). Our antimicrobial and antifungal activity studies of these peptides showed that BM-1 was much more active than IB-367 against Gram-positive bacteria and fungi, whereas BM-2 was inactive. ...

13p mobifone23 18-01-2013 24 2   Download

Antimicrobial peptides are effector molecules of the innate immune system. We recently showed that the human anti-microbial peptidesa-defensin and LL-37 bind to glycos-aminoglycans (heparin and dermatan sulphate). Here we demonstrate the obverse, i.e. structural motifs associated with heparin affinity (cationicity, amphipaticity, and con-sensus regions)may confer antimicrobial properties to a given peptide.

8p dell39 03-04-2013 13 2   Download

The first chemical investigation on Vietnamese medicinal plant Psychotria reevesii Wall. (Rubiaceae) led to the isolation and structural determination of -sitosterol and stigmasterol as a mixture, 1-octacosene, and asperglaucide from n-hexane- and CHCl3-soluble fractions of MeOH extract from the aerial parts of P. reevesii.

6p uocvong03 24-09-2015 23 2   Download

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài: Direct antimicrobial activity of antithrombin?

1p coxanh_7 31-10-2011 23 1   Download

Dendrimeric peptides selective for microbial surfaces have been developed to achieve broad antimicrobial activity and low hemolytic activity to human erythrocytes. The dendrimeric core is an asymmetric lysine branching tethered with two to eight copies of a tetrapeptide (R4) or an octapeptide (R8). The R4 tetrapeptide (RLYR) contains a putative microbial surface recognition BHHB motif (B ¼ basic, H ¼ hydrophobic amino acid) found in protegrins and tachyplesins whereas the octapeptide R8 (RLYRKVYG) consists of an R4 and a degenerated R4 repeat....

10p research12 01-06-2013 14 4   Download

To test a product exit differing from the substrate entrance in the active site of acetylcholinesterase (EC 3.1.1.7), we enlarged a channel located at the bottom of the active site gorge in the Drosophilaenzyme. Mutation of Trp83 to Ala or Glu widens the channel from 5 A˚ to 9 A ˚ .

6p media19 06-03-2013 26 3   Download

The GM2-activator protein (GM2AP) is an essential cofactor for the lyso-somal degradation of ganglioside GM2 by b-hexosaminidase A (HexA). It mediates the interaction between the water-soluble exohydrolase and its membrane-embedded glycolipid substrate at the lipid–water interface. Functional deficiencies in this protein result in a fatal neurological storage disorder, the AB variant of GM2 gangliosidosis.

10p inspiron33 26-03-2013 21 3   Download

Antimicrobial peptides are effector molecules of the innate immune system. We have recently shown that peptides containing multiples of the heparin-binding Cardin and Weintraub motifs AKKARA and ARKKAAKA exert antimicrobial activities. Here, we show that replacement of lysine and arginine in these motifs by histidine abrogates the antibacterial effects of these peptides.

8p inspiron33 26-03-2013 22 3   Download

Surfactant-like membranes containing the 21-residue peptide KLLLL-KLLLLKLLLLKLLLLK (KL4 ), have been clinically tested as a therapeu-tic agent for respiratory distress syndrome in premature infants. The aims of this study were to investigate the interactions between the KL4 peptide and lipid bilayers, and the role of both the lipid composition and KL4 structure on the surface adsorption activity of KL4 -containing membranes.

13p inspiron33 26-03-2013 18 3   Download

The epidermal mucus of fish species has been found to contain antimicro-bial proteins and peptides, which is of interest in regard to fish immunity. An acidic extract from the epidermal mucus of the Atlantic cod (Gadus morhua) was found to exhibit antimicrobial activity against Bacillus mega-terium, Escherichia coli andCandida albicans. This activity varied signifi-cantly when salt was added to the antimicrobial assay, and was eliminated by pepsin digestion.

10p fptmusic 12-04-2013 23 3   Download

As an adaptation process to the growth retardation provoked by the presence of nonlethal concentrations of ergosterol biosynthesis inhibitors, Ustilago maydis alters the ratio of linoleic to oleic acid bound to plasma membrane ´ complex lipids [Hernandez, A., Cooke, D.T., Lewis, M. & Clarkson, D.T. (1997) Microbiology 143, 3165–3174]. This alteration increases plasma membrane H+-ATPase hydrolytic activity.

6p research12 01-06-2013 15 3   Download

Snail is a multifunctional transcriptional factor that has been described as a repressor in many different contexts. It is also proposed as an activator in a few cases relevant to tumor progression and cell-cycle arrest. This study investigated the detailed mechanisms by which Snail upregulates gene expression of the CDK inhibitor p15 INK4b in HepG2 induced by the tumor promoter tetradecanoyl phorbol acetate (TPA).

17p mobifone23 18-01-2013 14 2   Download

Retinoic acid receptor (RAR) and retinoid X receptor are ligand-induced transcription factors that belong to the nuclear receptor family. The receptors are activated by small hydrophobic compounds, such as all-trans-retinoic acid and 9-cis-retinoic acid, respectively. Interestingly, these receptors are also targets for a number of exogenous compounds.

17p viettel02 22-02-2013 12 2   Download

Mitochondria regulate platelet metamorphosis induced by opsonized zymosan A – activation and long-term commitment to cell death Paola Matarrese1, Elisabetta Straface1, Giuseppe Palumbo2, Maurizio Anselmi2, Lucrezia Gambardella1, Barbara Ascione1, Domenico Del Principe2 and Walter Malorni1 1 Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanita’, Rome, Italy 2 Department of Pediatrics, University of Rome Tor Vergata, Italy Keywords aggregation; apoptosis; mitochondrial membrane potential; platelets; zymosan Correspondence P.

12p vinaphone15 27-02-2013 17 2   Download

Histone acetylation plays an integral role in the epigenetic regulation of gene expression. Transcriptional activity reflects the recruitment of oppo-sing classes of enzymes to promoter elements; histone acetyltransferases (EC 2.3.1.48) that deposit acetyl marks at a subset of histone residues and histone deacetylases that remove them.

13p vinaphone15 28-02-2013 12 2   Download