Research Center en Biotecnologia Aplicada

Tlaxcala Tlax, Mexico

Research Center en Biotecnologia Aplicada

Tlaxcala Tlax, Mexico

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Luna-Suarez S.,Research Center en Biotecnologia Aplicada | Medina-Godoy S.,Centro Interdisciplinario Of Investigacion Para El Desarrollo Integral Regional | Cruz-Hernandez A.,CINVESTAV | Paredes-Lopez O.,CINVESTAV
Journal of Biotechnology | Year: 2010

Amarantin is the predominant seed storage protein from amaranth. It shows a high content of essential amino acids, making this protein important from a nutritional viewpoint. The protein has two disulfide linked subunits: acidic and basic. Acidic subunit has the potential as a functional and nutraceutical protein, and it is structurally a good candidate for modification. In order to improve its functionality, the primary structure was modified in the third variable region of globulins 11S, by inserting four Val-Tyr antihypertensive peptides in tandem. The designed plasmid was expressed in Escherichia coli Origami (DE3) and then the expressed protein was purified. Mass spectrometry analysis was used to corroborate the identity of the protein by peptide mass fingerprinting; also, the modified peptide was fragmented and sequenced by mass spectrometry, corroborating thus the inserted residues. The hydrolyzed protein showed a high inhibitory activity of the angiotensin converting enzyme (IC 50 0.064mgml -1); it was nearly eightfold more active than the nonmodified protein. In spite that the nonmodified subunit is less active, its activity is comparable with other hydrolyzed proteins reported as high active inhibitors. The expressed and purified subunit after its engineered modification, may be useful for preventing hypertension and for other medical purposes. © 2010 Elsevier B.V.


Castro-Martinez C.,Research Center para el Desarrollo Integral Regional | Luna-Suarez S.,Research Center en Biotecnologia Aplicada | Paredes-Lopez O.,CINVESTAV
Journal of Biotechnology | Year: 2012

Amaranth seeds are considered as an excellent complementary source of food protein due to their balanced amino acid composition. Amarantin acidic subunit has the potential as a functional and nutraceutical protein, and it is structurally a good candidate for modification. The aim of this work was to improve its functionality, then the primary structure was modified into the third variable region of 11S globulins, by inserting antihypertensive peptides: four Val-Tyr in tandem and Arg-Ile-Pro-Pro in the C-terminal region. Modified protein was expressed in Escherichia coli Origami (DE3) and was purified. The culture conditions, including the culture media, temperature, agitation speed and air flow were tested in order to obtain an increased expression levels of the modified protein. A 2 3 factorial design was used for evaluate the effect of environmental conditions on modified protein production. The results indicated that the yield of modified protein could be increased by up 3-fold in bioreactor as compared with flask. In addition, the temperature, the agitation speed and the oxygen were significant factors on the expression of the antihypertensive protein. The maximum production was 99mg protein-L -1. The hydrolyzed protein showed a high inhibitory activity of the angiotensin converting enzyme (IC 50=0.047mgmL -1). © 2012 Elsevier B.V.


Absalon A.E.,Research Center en Biotecnologia Aplicada | Mariano-Matias A.,Research Center en Biotecnologia Aplicada | Vasquez-Marquez A.,Research Center en Biotecnologia Aplicada | Morales-Garzon A.,Investigacion Aplicada | And 3 more authors.
Virus Genes | Year: 2012

In Mexico, the number of cases of the highly virulent Newcastle disease virus is increasing. In 2005, an outbreak of Newcastle disease occurred on an egg laying hen farm in the state of Puebla despite vaccination with the LaSota strain. Farmers experienced a major drop in egg production as a consequence of a field challenge virus. In this study, we characterize the virus, APMV1/chicken/ Mexico/P05/2005, responsible for the outbreak. The virus is categorized as a velogenic virus with an intracranial pathogenicity index of 1.99 and a chicken embryo mean death time of 36 h. The complete genome length of the virus was sequenced as consisting of 15,192 bp. In addition, phylogenetic analysis classified the virus as a member of the class II, genotype V. The highly pathogenic nature of the virus has been linked to the amino acid sequence at the fusion protein cleavage site, which contains multiple basic amino acids (RRQKR;F). © Springer Science+Business Media, LLC 2012.


Diaz R.,Autonomous University of Tlaxcala | Alonso S.,Autonomous University of Tlaxcala | Sanchez C.,Autonomous University of Tlaxcala | Tomasini A.,Metropolitan Autonomous University | And 2 more authors.
BioResources | Year: 2011

Kinetic parameters of growth and laccase activity of five ATCC strains of Pleurotus ostreatus in submerged fermentation were evaluated. The best strain for laccase production and the time of maximum laccase activity were also determined. The greatest laccase activity (37490 U/L), laccase productivity (78 U/L h), specific growth rate (0.026/h), and specific rate of laccase production (119 U/gX h) were observed with the strain of P. ostreatus ATCC 32783. In general, the isoenzyme patterns were different in all the cases; however, all the strains showed two laccase bands in the same position in the gel. Not all strains responded in the same way to the addition of Cu in the culture medium. In general, the sensitivity to Cu could be used to select strains having high laccase activity for commercial exploitation.


Orduna-Diaz A.,National Institute of Astrophysics, Optics and Electronics | Trevino-Palacios C.G.,National Institute of Astrophysics, Optics and Electronics | Rojas-Lopez M.,Research Center en Biotecnologia Aplicada | Delgado-Macuil R.,Research Center en Biotecnologia Aplicada | And 2 more authors.
Materials Science and Engineering B: Solid-State Materials for Advanced Technology | Year: 2010

Hydrogenated amorphous silicon (a-Si:H) has found applications in flat panel displays, photovoltaic solar cell and recently has been employed in boron doped microbolometer array. We have performed electrical and structural characterizations of a-Si:H layers prepared by plasma enhanced chemical vapor deposition (PECVD) method at 540 K on glass substrates at different diborane (B2H6) flow ratios (500, 250, 150 and 50 sccm). Fourier transform infrared spectroscopy (FTIR) measurements obtained by specular reflectance sampling mode, show Si-Si, B-O, Si-H, and Si-O vibrational modes (611, 1300, 2100 and 1100 cm-1 respectively) with different strengths which are associated to hydrogen and boron content. The current-voltage curves show that at 250 sccm flow of boron the material shows the lowest resistivity, but for the 150 sccm boron flow it is obtained the highest temperature coefficient of resistance (TCR). © 2010 Elsevier B.V. All rights reserved.


Miche L.,IRD Montpellier | Miche L.,Aix - Marseille University | Moulin L.,IRD Montpellier | Chaintreuil C.,IRD Montpellier | And 6 more authors.
Environmental Microbiology | Year: 2010

Tropical aquatic legumes of the genus Aeschynomene are unique in that they can be stem-nodulated by photosynthetic bradyrhizobia. Moreover, a recent study demonstrated that two Aeschynomene indica symbionts lack canonical nod genes, thereby raising questions about the distribution of such atypical symbioses among rhizobial-legume interactions. Population structure and genomic diversity were compared among stem-nodulating bradyrhizobia isolated from various Aeschynomene species of Central America and Tropical Africa. Phylogenetic analyses based on the recA gene and whole-genome amplified fragment length polymorphism (AFLP) fingerprints on 110 bacterial strains highlighted that all the photosynthetic strains form a separate cluster among bradyrhizobia, with no obvious structuring according to their geographical or plant origins. Nod-independent symbiosis was present in all sampling areas and seemed to be linked to Aeschynomene host species. However, it was not strictly dependent on photosynthetic ability, as exemplified by a newly identified cluster of strains that lacked canonical nod genes and efficiently stem-nodulated A. indica, but were not photosynthetic. Interestingly, the phenotypic properties of this new cluster of bacteria were reflected by their phylogenetical position, as being intermediate in distance between classical root-nodulatingBradyrhizobium spp. and photosynthetic ones. This result opens new prospects about stem-nodulating bradyrhizobial evolution. © 2009 Society for Applied Microbiology and Blackwell Publishing Ltd.


Troconis-Torres I.G.,National Polytechnic Institute of Mexico | Rojas-Lopez M.,Research Center en Biotecnologia Aplicada | Hernandez-Rodriguez C.,National Polytechnic Institute of Mexico | Villa-Tanaca L.,National Polytechnic Institute of Mexico | And 4 more authors.
Journal of Biomedicine and Biotechnology | Year: 2012

The genus Capsicum provides antioxidant compounds, such as phenolics and carotenoids, into the diet. In Mexico, there is a wide diversity of species and varieties of chilli peppers, a fruit which has local cultural and gastronomic importance. In the present study, the relationship of the carotenoid and phenolic profiles with the RAPD fingerprint of three different commercial cultivars of chilli peppers of seven regions of Mexico was investigated. Through RAPD, the species of chilli were differentiated by means of different primers (OPE-18, MFG-17, MFG-18, C51, and C52). The genetic distance found with OPE 18 was in the order of 2.6. The observed differences were maintained when the chromatographic profile of carotenoids, and the molecular markers were analyzed, which suggest a close relationship between carotenoids and the genetic profile. While the chromatographic profile of phenols and the molecular markers were unable to differentiate between genotypes of chilli peppers. In addition, by using infrared spectroscopy and statistical PCA, differences explained by geographic origin were found. Thus, this method could be an alternative for identification of chilli species with respect to their geographic origin. Copyright © 2012 Ivonne Guadalupe Troconis-Torres et al.


Diaz R.,Autonomous University of Tlaxcala | Sanchez C.,Autonomous University of Tlaxcala | Bibbins-Martinez M.D.,Research Center en Biotecnologia Aplicada | Diaz-Godinez G.,Autonomous University of Tlaxcala
African Journal of Microbiology Research | Year: 2011

The number of laccase isoenzymes and laccase activities of Pleurotus ostreatus in buffered and nonbuffered media were determined. In both culture media, the initial pH was adjusted to 3.5. Similar laccases activity (100-500 U/L) was observed in the range of 100-400 h (approximately) of fermentation in both media. Buffered culture medium yielded higher laccases activities (3200 U/L) at 500 h of fermentation than those observed in non-buffered culture medium (450 U/L). One laccase isoenzyme was produced during the entire fermentation process in both media. In the non-buffered medium, an additional isoenzyme of lower molecular weight than that produced in the entire fermentation process was produced at the beginning of the exponential phase of growth when the pH reached a value of 6.5. These results suggest that the fungus produces metabolites that modify the pH of the medium and that some laccases isoenzymes are regulated by pH signals. This is the first report on zymogram patterns from laccases activity of P. ostreatus at low pH. © 2011 Academic Journals.


PubMed | Research Center en Biotecnologia Aplicada, Laboratorio Of Modelado Molecular Y Diseno Of Farmacos, Laboratorio Of Bioquimica Y Biofisica Computacional, Laboratorio Of Inmunologia Molecular and 3 more.
Type: Journal Article | Journal: Journal of molecular recognition : JMR | Year: 2015

Computational identification of potential epitopes with an immunogenic capacity challenges immunological research. Several methods show considerable success, and together with experimental studies, the efficiency of the algorithms to identify potential peptides with biological activity has improved. Herein, an epitope was designed by combining bioinformatics, docking, and molecular dynamics simulations. The hemagglutinin protein of the H1N1 influenza pandemic strain served as a template, owing to the interest of obtaining a scheme of immunization. Afterward, we performed enzyme-linked immunosorbent assay (ELISA) using the epitope to analyze if any antibodies in human sera before and after the influenza outbreak in 2009 recognize this peptide. Also, a plaque reduction neutralization test induced by virus-neutralizing antibodies and the IgG determination showed the biological activity of this computationally designed peptide. The results of the ELISAs demonstrated that the serum of both prepandemic and pandemic recognized the epitope. Moreover, the plaque reduction neutralization test evidenced the capacity of the designed peptide to neutralize influenza virus in Madin-Darby canine cells.


PubMed | CINVESTAV, Research Center en Biotecnologia Aplicada and National Autonomous University of Mexico
Type: | Journal: Enzyme and microbial technology | Year: 2016

Zymomonas mobilis genes encoding INVA and INVB were expressed in Pichia pastoris, under the control of the strong AOX1 promoter, and the recombinant enzymes were named INVAAOX1 and INVBAOX1. The expression levels of INVAAOX1 (1660 U/mg) and INVBAOX1 (1993 U/mg) in P. pastoris were 9- and 7-fold higher than those observed for the native INVA and INVB proteins in Z. mobilis. INVAAOX1 and INVBAOX1 displayed a 2- to 3-fold higher substrate affinity, and a 2- to 200-fold higher catalytic efficiency (kcat/KM) than that observed for native INVA and INVB from Z. mobilis. Positive Schiff staining of INVAAOX1 and INVBAOX1 suggested a glycoprotein nature of both invertases. After deglycosylation of these enzymes, denoted D-INVAAOX1 and D-INVBAOX1, they exhibited a 1.3- and 3-fold lower catalytic efficiency (107 and 164 s(-1) mM(-1), respectively), and a 1.3- to 5-fold lower thermal stability than the glycosylated forms at temperatures of 35-45 C. After deglycosylation no effect was observed in optimal pH, being of 5.5 for INVAAOX1, INVBAOX1, D-INVAAOX1 and D-INVBAOX1. The invertase activity of both enzymes increased in 80% (INVAAOX1) and 20% (INVBAOX1) in the presence of Mn(2+) at 1 mM and 5 mM, respectively. INVAAOX1 and INVBAOX1 were highly active at sucrose concentrations of up to 400 and 300 mM, respectively; however, the tolerance to sucrose decreased to 300 mM for D-INVAAOX1. Our findings suggest that glycosylation of INVAAOX1 and INVBAOX1 plays an important role in their thermal stability, catalytic efficiency, and tolerance to sucrose. In conclusion, the expression of INVA and INVB from Z. mobilis in P. pastoris yields new catalysts with improved catalytic properties, making them suitable candidates for a number of industrial applications or for the improvement of ethanol production from cane molasses.

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