Time filter

Source Type

Bucharest, Romania

Kanthala S.,University of Louisiana at Monroe | Gauthier T.,Biotechnology Laboratory | Satyanarayanajois S.,University of Louisiana at Monroe
Biopolymers | Year: 2014

Human epidermal growth factor receptor-2 (HER2) is a tyrosine kinase family protein receptor that is known to undergo heterodimerization with other members of the family of epidermal growth factor receptors (EGFR) for cell signaling. Overexpression of HER2 and deregulation of signaling has implications in breast, ovarian, and lung cancers. We have designed several peptidomimetics to block the HER2-mediated dimerization, resulting in antiproliferative activity for cancer cells. In this work, we have investigated the structure-activity relationships of peptidomimetic analogs of Compound 5. Compound 5 was conformationally constrained by N- and C-terminal modification and cyclization as well as by substitution with d-amino acids at the N-and C-termini. Among the compounds studied in this work, a peptidomimetic Compound 21 with d-amino acid substitution and its N- and C-termini capped with acetyl and amide functional groups and a reversed sequence compared to that of Compound 5 exhibited better antiproliferative activity in HER2-overexpressed breast, ovarian, and lung cancer cell lines. Compound 21 was further evaluated for its protein-protein interaction (PPI) inhibition ability using enzyme fragment complementation assay, proximity ligation assay, and Western blot analysis. Results suggested that Compound 21 is able to block HER2:HER3 interaction and inhibit phosphorylation of the kinase domain of HER2. The mode of binding of Compound 21 to HER2 protein was modeled using a docking method. Compound 21 seems to bind to domain IV of HER2 near the PPI site of EGFR:HER2, and HER:HER3 and inhibit PPI. Copyright © 2013 Wiley Periodicals, Inc. Source

Shimura M.,Biotechnology Laboratory
Quarterly Report of RTRI (Railway Technical Research Institute) (Japan) | Year: 2010

Pollution of soil and underground water, including leakage of gasoline from subterranean storage, poses a significant risk to living organisms. An approach using microorganisms to remediate polluted environments is applicable to locations beneath buildings and bridges. However, no monitoring method for bioremediation activity in soil has yet been developed. It is essential to estimate biological activity in soil to proceed with remediation activity. Accordingly, we established a method that combines bacteria detection in soil using spectral analysis with the use of genetically modified bacteria that release green fluorescence with remediation activity. Source

Meza P.,Center for Advanced Horticultural Studies | Aballay E.,University of Chile | Hinrichsen P.,Biotechnology Laboratory
Nematropica | Year: 2012

Xiphinema index is a major plant parasitic nematode for vineyards, both as a root pathogen and as a vector for Grape Fanleaf virus. In Chile it has a wide distribution, causing considerable damage to Vitis vinifera. The main morphological and morphometric features that have been used for its identification are related to the vulval position and the presence of a mucro on the tail. However, these features have a limited discrimination capacity, as identification is more complicated in a highly complex matrix such as the soil, where a mixture of species coexists. This situation has motivated the search for and the application of molecular techniques with increased resolution power. This investigation shows the results of morphological and molecular characterization of X. index isolates from Chile. The complete ITS regions (ITS1 and ITS2) were sequenced revealing very low intraspecific diversity, less than 1% or the most divergent available sequences. This coincided with the low level of differences detected at the morphometric level. Source

Shekhawat M.S.,Biotechnology Laboratory | Kannan N.,Biotechnology Unit | Manokari M.,Biotechnology Laboratory
South African Journal of Botany | Year: 2015

An efficient micropropagation protocol has been developed successfully for Morinda coreia Buch.-Ham. by culturing nodal segments. The explants were washed, sterilized with HgCl2 and inoculated on semi-solid Murashige and Skoog (MS) medium containing various concentrations and combinations of plant growth regulators (PGRs). Shoot bud initiation was observed after one week and 8.6±0.32 shoots (per explant) harvested after five weeks on MS medium with 4.0mgl-1 concentration of 6-benzylaminopurine (BAP). The regenerated shoots were further multiplied on semi-solid MS medium augmented with 2.0mgl-1 BAP+1.0mgl-1 Kinetin (Kin). Maximum 24.5±0.34 shoots per explant was obtained after five weeks on this media combination. The long (4-5cm) and healthy shoots were rooted in vitro with 100% success rate on half strength MS medium+1.0mgl-1 indole-3 butyric acid (IBA). Rooting and acclimatization were achieved simultaneously by ex vitro rooting method using 200mgl-1 IBA for 5min with very good success rate (28.67±05.51 roots per shoot with 100% response). The rooted shoots were transferred to the greenhouse for acclimatization for 4-5weeks. The hardened plantlets were finally shifted to the field for further growth in the natural conditions after another five weeks. This is the first report on micropropagation of M. coreia, which can be successfully used for the large-scale multiplication and conservation of germplasm of this important medicinal plant. © 2015 South African Association of Botanists. Source

Rathore M.S.,Jai Narain Vyas University | Rathore M.S.,Biotechnology Laboratory | Shekhawat N.S.,Jai Narain Vyas University
Environmental and Experimental Botany | Year: 2013

Leptadenia reticulata (Retz.) Wight& Arnis an important medicinal plant, belongs to the family AsclepiadaceaeThis plant is known for its medicinal uses since 4500 BCPresently this is an endangered species (Arya et al., 2003)Six shoots (2-4cm long) per node differentiated on MS medium+5.0mg/l of BAP+additivesIncorporation of additives in the culture medium promoted growth of culturesThe shoots differentiated per explant were repeatedly transferred on to fresh MS+1.0mg/l of BAP+0.1mg/l of NAA and additivesThe regenerated shoots were subcultured for further multiplication on MS+1.0mg/l BAP+0.5mg/l Kin+2-iP (0.5mg/l) and 0.1mg/l of NAA+additives regularly after an interval of 3 weeksAddition of ammonium sulphate in the medium resulted in increase in shoot number and promoted elongation also growth of cultures was sustained even if subculturing was delayed (26±2 days)Success was also achieved in defining protocol for in vitro regeneration of shoots from petiole derived callusShoots regenerated in vitro by both processes were rooted in vitro on 1/4 strength of MS medium+3.0mg/l of IBA after 15-20 daysCent percent of the shoots rooted ex vitro, if the in vitro regenerated shoots were treated with 200mg/l of IBAThe in vitro-ex vitro rooted plantlets were hardened under different regimes of temperature and humidity in a greenhouseThe hardened plantlets were transferred to soil in polybagsMore than 95% plants survived in field conditionsTotal dry biomass harvested per year was 2800kg/acre © 2010 Elsevier B.V. Source

Discover hidden collaborations