Author: MARTHA LETICIA SANTOS MARTINEZ
"In this work we present the NADH-dependent Ta1316 alcohol dehydrogenese (ADH) characterization for its reducingreaction in the presence of aldehydes, ketones and keto-esters. In the presence of 2 mM acetaldehyde, Ta1316 ADHshowed a remarkable thermal activity, displaying activity at temperatures up tp 90”C and low pH with a requirement ofZ+2to reach its maximum activity. In contrast to other characterized ADHs, Ta1316 ADH reduces methyl pyruvate, analpha-ketoester as its preferred substrate. We conclude that Ta1316 ADH’s principalfunction is the reduction of substratesand is potentially an enzyme that can be used in biotechnology, as erll as in industrial applications. "
"En este trabajo presentamos la caracterización de la actividad enzimática reductora de la enzima alcohol deshidrogenasa (ADH) Ta1316 dependiente de NADH en presencia de aldehídos, cetonas y ceto ́esteres. La ADH Ta1316 mostr ́o estabilidadt ́ermica notable con actividad m ́axima a temperatura de 90”C y pH ac ́ıdico en presencia del cofactor Zn+2y acetaldeh ́ıdo2 mM. En contraste con otras ADHs caracterizadas, Ta1316 es capaz de reducir metil-piruvato, un alfa-cetoéster como susustrato preferido. Concluimos que la función principal de la Ta1316 ADH es la reducción de sustratos y es una enzima que podría ser utilizada potencialmente en aplicaciones biotecnológicas e industriales."
"Umbilical cord blood transplantation is clinically limited by its low progenitor cell content. Ex vivo expansion has become an alternative to increase the cell dose available for transplants. Expansion has been evaluated in several ways such as static cultures combining growth factors or mimicking the natural microenvironment using co-culture systems. However, static cultures have a small volume capacity and therefore large-scale expansion has been addressed using bioreactors. These and other biotechnological approaches for the expansion of hematopoietic progenitors and their utility to study several aspects of hematopoietic stem cell biology are discussed here."
"Sequencing of the Thermoplasma acidophilum genome revealed a new gene, taa43, which codes for a 43-kDa protein containing one AAA domain; we therefore termed it Thermoplasma AAA ATPase of 43 kDa (TAA43). Close homologs of TAA43 are found only in related Thermoplasmales, e.g. T. volcanium and Ferroplasma acidarmanus, but not in other Archaea. A detailed phylogenetic analysis showed that TAA43 and its homologs belong to the ‘meiotic’ branch of the AAA family. Although AAA proteins usually assemble into high-molecular-weight complexes, native TAA43 is predominantly dimeric except for a minor fraction eluting in the void volume of a sizing column. Wild-type and mutant TAA43 proteins were overexpressed in Escherichia coli, purified as dimers and characterized functionally. Since the canonical proteasome activating nucleotidase is not present in Thermoplasmales, TAA43 was tested for stimulation of proteasome activity, which was, however, not detected. Interestingly, immunoprecipitation analysis with TAA43 specific antibodies found a fraction of native TAA43 associated with Thermoplasma ribosomal proteins."
"Culturable psychrophilic prokaryotes were obtained of samples of glacier sediment, seaside mud, glacier melted ice, and Deschampsia antarctica rhizosphere from Collins glacier, Antarctica. The taxonomic classification was done by a culture-dependent molecular approach involving the Amplified Ribosomal DNA Restriction Analysis. Two hundred sixty colonies were successfully isolated and sub-cultivated under laboratory conditions. The analysis showed a bacterial profile dominated by Beta-proteobacteria (35.2%) followed by Gamma-proteobacteria (18.5%), Alpha-proteobacteria (16.6%), Gram-positive with high GC content (13%), Cytophaga–Flavobacterium–Bacteroides (13%) and Gram-positive with low GC content (3.7%). Eleven of the isolates have been reported previously and the others microorganisms remain uncharacterized. The isolated microorganisms here could be a potential source for biotechnological products, such as cold-active enzymes and secondary metabolites."
"Aims: To identify the yeast and bacteria present in the mezcal fermentation from Agave salmiana.
Methods and Results: The restriction and sequence analysis of the amplified region, between 18S and 28S rDNA and 16S rDNA genes, were used for the identification of yeast and bacteria, respectively. Eleven different micro‐organisms were identified in the mezcal fermentation. Three of them were the following yeast: Clavispora lusitaniae, Pichia fermentans and Kluyveromyces marxianus. The bacteria found were Zymomonas mobilis subsp. mobilis and Zymomonas mobilis subsp. pomaceae, Weissella cibaria, Weissella paramesenteroides, Lactobacillus pontis, Lactobacillus kefiri, Lactobacillus plantarum and Lactobacillus farraginis.
Conclusions: The phylogenetic analysis of 16S rDNA and ITS sequences showed that microbial diversity present in mezcal is dominated by bacteria, mainly lactic acid bacteria species and Zymomonas mobilis. Pichia fermentans and K. marxianus could be micro‐organisms with high potential for the production of some volatile compounds in mezcal.
Significance and Impact of the Study: We identified the community of bacteria and yeast present in mezcal fermentation from Agave salmiana."
MARTHA LETICIA SANTOS MARTINEZ MA. FABIOLA LEON GALVAN ERIKA NAHOMY MARINO MARMOLEJO ANA PAULINA BARBA DE LA ROSA ANTONIO DE LEON RODRIGUEZ ROBERTO FIDENCIO GONZALEZ AMARO RAMON GERARDO GUEVARA GONZALEZ (2011)
"The aim of this study was to identify the gene expression profile in biopsies of patients with cervical intraepithelial neoplasia (CIN) 1, CIN 2, CIN 3, and microinvasive cancer by suppression subtractive hybridization and Southern blotting. After analyzing 1,800 cDNA clones, we found 198 upregulated genes, 166 downregulated, and no significant change of gene expression in 86 clones (p = 0.005). These results were validated by Northern blot analysis (p = 0.0001) in the identification of 28 overexpressed and 7 downregulated transcripts. We observed a set of genes related to the Notch signaling pathway that may be involved in the transformation of cervical cells and in the development to malignancy. The differentially expressed genes may provide useful information about the molecular mechanisms involved in human cervical carcinoma and as diagnostic markers."
"Genetic background and T-cell expansion have been associated as the most important factors for psoriasis susceptibility in the Caucasian population. This study was performed to identify the T cell receptor Vβ repertoire and HLA-Cw genotype in two Mexican groups with severe chronic plaque-type psoriasis. HLA-C typing was performed to detect the allele pattern associated with the disease by sequence-specific primer-polymerase chain reaction. In parallel, RT-PCR and Western blot were used for the identification of the TCR Vβ repertoire. We found a wide variety of HLA-C alleles displayed with a preference to HLA-Cw *07 as the most representative allele in the group of patients. TCR Vβ-2 and Vβ-7 clone-type frequencies were statistically significant (p of 0.0280) when compared to other TCR Vβ expressed in the two groups. We found notable differences both in the HLA-C genotype and TCR Vβ repertoire in the groups of patients studied. Since Mexican individuals are genetically different from the Caucasian population, we suggest that due to these differences the susceptibility to disease and activation of T-cells for a proper immune response may be affected."
ERIKA NAHOMY MARINO MARMOLEJO CITLALLI TORNEZ BENITEZ VANIA ELVIRA BONIFAZ PENA MABEL GUZMAN RODRIGUEZ HUGO ENRIQUE LOPEZ GONZALEZ ABEL GUTIERREZ ORTEGA MARTHA LETICIA SANTOS MARTINEZ MARIO ALBERTO FLORES VALDEZ (2011)
"Mycobacterium tuberculosis employs a number of strategies to subvert host signaling events, leading to its persistence within macrophages. Upon infection, Mycobacterium bovis BCG induce the expression of suppressor of cytokine signaling 3 (socs3), in a Toll-like receptor 2 (TLR2)-Notch1-dependent manner. Purified phosphatidyl inositol di-mannosides (a TLR2 agonist) act as an inducer for the Notch1-socs3 pathway. This prompted us to analyze other TLR2 agonists seeking for additional molecules that may affect this pathway. We found that lipoprotein LprA, as well as glycolipids lipomannan (LM), and mannose-capped lipoarabinomannan (ManLAM) treatment of murine macrophages resulted in stimulation of notch1 and socs3 transcription."
HUGO SERGIO AGUILAR HERNANDEZ MARTHA LETICIA SANTOS MARTINEZ MA. FABIOLA LEON GALVAN ALBERTO BARRERA PACHECO EDUARDO ESPITIA RANGEL ANTONIO DE LEON RODRIGUEZ RAMON GERARDO GUEVARA GONZALEZ ANA PAULINA BARBA DE LA ROSA (2011)
"Calcium (Ca2+) is a critical ion for the growth and development of plants and plays an important role in signal transduction pathways in response to biotic and abiotic stresses. We investigated the Ca2+ stress responsive-genes in amaranth leaves by using the suppression subtractive hybridization technique. Screening of the libraries generated 420 up-regulated transcripts and 199 down-regulated transcripts. The differentially expressed transcripts were associated with general stress response, transcription factors, gene regulation, signal transduction, and some other with unknown function. Selected genes were used to study their differential regulation by sqRT-PCR. Among the up-regulated transcripts, a fragment containing the motif of C3HC4-type RING-Zinc family was further characterized. The ORF of amaranth zinc finger protein (AhZnf) has a closer relationship with its ortholog from Ricinus communis while is distantly related to the Arabidopsis thaliana C3HC4-type ortholog. We have identified a novel putative zinc finger protein along with other novel proteins such as the wall associated kinase, phosphoinositide binding protein, and rhomboid protease involved in response to Ca2+ stress in amaranth leaves."