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Understanding a Core Pilin of the Type IVa Pili of Acidithiobacillus thiooxidans, PilV
( Araceli Hernández-sánchez ),( Edgar D. Páez-pérez ),( Elvia Alfaro-saldaña ),( Vanesa Olivares-illana ),( J. Viridiana García-meza ) 한국미생물생명공학회 2024 Journal of microbiology and biotechnology Vol.34 No.3
Pilins are protein subunits of pili. The pilins of type IV pili (T4P) in pathogenic bacteria are well characterized, but anything is known about the T4P proteins in acidophilic chemolithoautotrophic microorganisms such as the genus Acidithiobacillus. The interest in T4P of A. thiooxidans is because of their possible role in cell recruitment and bacterial aggregation on the surface of minerals during biooxidation of sulfide minerals. In this study we present a successful ad hoc methodology for the heterologous expression and purification of extracellular proteins such as the minor pilin PilV of the T4P of A. thiooxidans, a pilin exposed to extreme conditions of acidity and high oxidation-reduction potentials, and that interact with metal sulfides in an environment rich in dissolved minerals. Once obtained, the model structure of A. thiooxidans PilV revealed the core basic architecture of T4P pilins. Because of the acidophilic condition, we carried out in silico characterization of the protonation status of acidic and basic residues of PilV in order to calculate the ionization state at specific pH values and evaluated their pH stability. Further biophysical characterization was done using UV-visible and fluorescence spectroscopy and the results showed that PilV remains soluble and stable even after exposure to significant changes of pH. PilV has a unique amino acid composition that exhibits acid stability, with significant biotechnology implications such as biooxidation of sulfide minerals. The biophysics profiles of PilV open new paradigms about resilient proteins and stimulate the study of other pilins from extremophiles.
Alma Laura Sánchez-Casillas,Horacio Rivera,Anna Gabriela Castro-Martínez,José Elías García-Ortiz,Carlos Córdova-Fletes,Paul Mendoza-Pérez 대한진단검사의학회 2017 Annals of Laboratory Medicine Vol.37 No.1
Dear Editor, The rec(8)dup(8q)inv(8)(p23.1q22.1) chromosome associated with San Luis Valley Syndrome (SLVS OMIM 179613) is usually diagnosed in Hispanic patients from the USA Southwest where a founder carrier Spaniard lived around 1800 [1, 2]. This rec(8) has an 8q duplication of 47.90 Mb and an 8p deletion of 11.65 Mb [3, 4]. Excluding two de novo rec(8)dup q chromosomes characterized only by G-bands and included in a recent compilation [5], cytogenomic analyses identified nine comparable de novo der(8)dup q/del p chromosomes with or without a simultaneous 8p gain. We describe a Mexican mestizo girl with a de novo SLVS-like der(8) but with a concomitant 8p22p23.1 duplication.
E. García-Hernández,C.G. Aguilar-Madera,E.C. Herrera-Hernández,R. Ocampo-Pérez,E. Bailón-García,Farid B. Cortés 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.93 No.-
In this work, a mathematical formulation based on fundamental principles of momentum and masstransport with a kinetic adsorption model at the liquid-solid interface is proposed. This formulation wasnumerically solved and used for the interpretation of adsorption rate data of phenol onto an activatedcarbon cloth in a stirred tank adsorber under different agitation rates. The mathematical model solutionwas compared with the obtained by mathematical models that neglect the local velocity andconcentration profiles in the solution; external mass transfer model (EMTM) and thefirst-order kineticmodel (FOM). The results showed that under all studied stirring speeds (30 200 rpm) the proposedmodel was able to capture the dynamics of the concentration decay curves, while EMTM and FOM modelswere only able to interpret the data at high stirring speeds, indicating that velocity profiles play animportant role during phenol adsorption. Particular “wake zones” were identified behind the mobileadsorbent, which importantly promotes the transport of solute toward the activated carbon cloth. As aresult, it was found that convective transport is much more important than diffusive transport in thesolution.
César Hidalgo-García,José Miguel Tricás-Moreno,Orosia Lucha-López,Elena Estebanezde Miguel,Elena Bueno-Gracia,Silvia Pérez-Guillén,Pablo Fanlo-Mazas,Alazne Ruiz-de-Escudero,John Krauss 국제물리치료학회 2016 Journal of International Academy of Physical Ther Vol.7 No.1
The purpose of this study is to explore the effects of mobilization of C0-C1 and C7-T1 applied to asymptomatic individuals with reduced upper cervical rotation during the FRT. Design: parallel randomized controlled trial. 48 subjects(38.52 years±15.13) with C1-C2 rotation hypomobility in TFR joined the study and were randomized into three groups(C0, C7, control group). FRT in both directions was measured before and after the intervention. C0 intervention consisted of a dorsal translatoric mobilization of C0-C1 in the cervical neutral position. C7 intervention consisted of a ventral cranial translatoric mobilization of C7- T1 in neutral position and the control group maintained a supine position. C0 group experienced a FRT ROM to the restricted side increase of 17.64。(SD=4.55), that was significantly greater (P<0.001) than 5.95。 (SD=4.81) of the C7 group and 2.45。(SD=5.05) of the control group. The results showed that a dorsal translatoric mobilization of C0-C1 in neutral position restored the physiological FRT mobility in subjects with C1-C2 hypomobility and experienced statistical significant improvement in FRT as compared to a C7-T1 translatoric mobilization and a control group. (Level of evidence: 1b).
( Francisco J. Pérez-de Los Santos ),( Luis Fernando García-ortega ),( Karina Robledo-márquez ),( Jesús Guzmán-moreno ),( Lina Riego-ruiz ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.5
After Candida albicans, Candida glabrata is one of the most common fungal species associated with candidemia in nosocomial infections. Rapid acquisition of nutrients from the host is important for the survival of pathogens which possess the metabolic flexibility to assimilate different carbon and nitrogen compounds. In Saccharomyces cerevisiae, nitrogen assimilation is controlled through a mechanism known as Nitrogen Catabolite Repression (NCR). NCR is coordinated by the action of four GATA factors; two positive regulators, Gat1 and Gln3, and two negative regulators, Gzf3 and Dal80. A mechanism in C. glabrata similar to NCR in S. cerevisiae has not been broadly studied. We previously showed that in C. glabrata, Gln3, and not Gat1, has a major role in nitrogen assimilation as opposed to what has been observed in S. cerevisiae in which both factors regulate NCR-sensitive genes. Here, we expand the knowledge about the role of Gln3 from C. glabrata through the transcriptional analysis of BG14 and gln3Δ strains. Approximately, 53.5% of the detected genes were differentially expressed (DEG). From these DEG, amino acid metabolism and ABC transporters were two of the most enriched KEGG categories in our analysis (Up-DEG and Down-DEG, respectively). Furthermore, a positive role of Gln3 in AAA assimilation was described, as was its role in the transcriptional regulation of ARO8. Finally, an unexpected negative role of Gln3 in the gene regulation of ABC transporters CDR1 and CDR2 and its associated transcriptional regulator PDR1 was found. This observation was confirmed by a decreased susceptibility of the gln3Δ strain to fluconazole.
Claudia Carolina Pérez-Castro,Alexandre Kormanovski,Gustavo Guevara-Balcázar,María del Carmen Castillo-Hernández,José Rubén García-Sánchez,Ivonne María Olivares-Corichi,Pedro López-Sánchez,Iván Rubio- 대한약리학회 2023 The Korean Journal of Physiology & Pharmacology Vol.27 No.1
The mechanism is unclear for the reported protective effect of hyperbaric oxygen preconditioning against oxidative stress in tissues, and the distinct effects of hyperbaric oxygen applied after stress. The trained mice were divided into three groups: the control, hyperbaric oxygenation preconditioning, and hyperbaric oxygenation applied after mild (fasting) or hard (prolonged exercise) stress. After preconditioning, we observed a decrease in basal levels of nitric oxide, tetrahydrobiopterin, and catalase despite the drastic increase in inducible and endothelial nitric oxide synthases. Moreover, the basal levels of glutathione, related enzymes, and nitrosative stress only increased in the preconditioning group. The control and preconditioning groups showed a similar mild stress response of the endothelial and neuronal nitric oxide synthases. At the same time, the activity of all nitric oxide synthase, glutathione (GSH) in muscle, declined in the experimental groups but increased in control during hard stress. The results suggested that hyperbaric oxygen preconditioning provoked uncoupling of nitric oxide synthases and the elevated levels of GSH in muscle during this study, while hyperbaric oxygen applied after stress showed a lower level of GSH but higher recovery post-exercise levels in the majority of antioxidant enzymes. We discuss the possible mechanisms of the redox response and the role of the nitric oxide in this process
Karla F. García-Verdugo,Andya J. Ramírez-Irigoyen,Mónica Castillo-Ortega,Dora E. Rodríguez-Félix,Jesús M. Quiroz-Castillo,Judith Tánori-Córdova,Francisco Rodríguez-Félix,Antonio Ledezma-Pérez,Teresa d 한국고분자학회 2022 Macromolecular Research Vol.30 No.6
A novel semi-interpenetrating polymer network (s-IPN) based on the entrapment of a thermosensitive polymer, the poly(vinyl methyl ether) (PVME), within a crosslinked 3D structure of poly(vinyl alcohol) (PVA) and poly(vinyl methyl etheralt- maleic acid) (COP) was synthesized by an autoclaving process. The preparation method avoids the use of toxic crosslinkers and allows the simultaneous sterilization of material. The PVA/COP/PVME hydrogel were characterized by Fourier transform infrared spectroscopy, thermal techniques, swelling kinetic measurements, scanning electron microscopy, and rheological analysis. The entrapment of PVME within the hydrated polymer framework significantly modified its transition temperature at pH 7.4 and pH 3 conditions. The swelling kinetics of the s-IPN were dependent on pH (7.4, 3 and 1), and temperature (25 and 37℃). The interpenetrated polymer chains reduced the internal pore sizes of crosslinked network without altering its elastic, solid-like behavior. The loading and in vitro release of 5-fluorouracil, a chemotherapeutic agent, from hydrogel systems were studied at different temperature and pH values. The hydrogels showed a sustained drug release up to 5 h at 37℃, in different pH media. The s-IPN exhibited a promising performance for a range of biomedical applications, in particular, for the controlled drug delivery in response to the pH and temperature conditions.
C.E. Rodríguez-García,N. Perea-López,S.P. DenBaars,G.A. Hirata 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.5
Red-emitting phosphor powders of SrIn2O4 activated with Eu3+ ions were synthesized by a high pressure assisted combustion method. X-ray diffraction analysis of the crystalline properties of these powders revealed single phase SrIn2O4 for Eu concentrations up to 4 atomic % of Eu. The photo and cathodoluminescence emission spectra of SrIn2O4: Eu3+ powder shows bright red emission mainly caused by the 5D0→7F2 intra-shell transition of Eu3+. Furthermore, photoluminescence excitation (PLE) spectroscopy revealed that an efficient energy transfer from the SrIn2O4 host lattice onto the Eu ions is accomplished in addition to the excitation band peaked at λ = 396 nm that directly excites the Eu ions, making this material an excellent candidate for applications in solid state white-emitting lamps. Red-emitting phosphor powders of SrIn2O4 activated with Eu3+ ions were synthesized by a high pressure assisted combustion method. X-ray diffraction analysis of the crystalline properties of these powders revealed single phase SrIn2O4 for Eu concentrations up to 4 atomic % of Eu. The photo and cathodoluminescence emission spectra of SrIn2O4: Eu3+ powder shows bright red emission mainly caused by the 5D0→7F2 intra-shell transition of Eu3+. Furthermore, photoluminescence excitation (PLE) spectroscopy revealed that an efficient energy transfer from the SrIn2O4 host lattice onto the Eu ions is accomplished in addition to the excitation band peaked at λ = 396 nm that directly excites the Eu ions, making this material an excellent candidate for applications in solid state white-emitting lamps.
Jaqueline López-Ochoa,J. Fernando Montes-García,Candelario Vázquez,Patricia Sánchez-Alonso,Victor M. Pérez-Márquez,Patrick J. Blackall,Sergio Vaca,Erasmo Negrete-Abascal 한국미생물학회 2017 The journal of microbiology Vol.55 No.9
Gallibacterium, which is a bacterial pathogen in chickens, can form biofilms. Amyloid proteins present in biofilms bind Congo red dye. The aim of this study was to characterize the cell-surface amyloid-like protein expressed in biofilms formed by Gallibacterium strains and determine the relationship between this protein and curli, which is an amyloid protein that is commonly expressed by members of the Enterobacteriaceae family. The presence of amyloid-like proteins in outer membrane protein samples from three strains of G. anatis and one strain of Gallibacterium genomospecies 2 was evaluated. A protein identified as elongation factor-Tu (EF-Tu) by mass spectrometric analysis and in silico analysis was obtained from the G. anatis strain F149T. This protein bound Congo red dye, cross-reacted with anti-curli polyclonal serum, exhibited polymerizing properties and was present in biofilms. This protein also reacted with pooled serum from chickens that were experimentally infected with G. anatis, indicating the in vivo immunogenicity of this protein. The recombinant EF-Tu purified protein, which was prepared from G. anatis 12656-12, polymerizes under in vitro conditions, forms filaments and interacts with fibronectin and fibrinogen, all of which suggest that this protein functions as an adhesin. In summary, EF-Tu from G. anatis presents amyloid characteristics, is present in biofilms and could be relevant for the pathogenesis of G. anatis.