Proteomic analysis of cold adaptation in a Siberian permafrost bacterium – Exiguobacterium sibiricum 255–15 by two-dimensional liquid separation coupled with mass spectrometry

Bacterial cold adaptation in Exiguobacterium sibiricum 255–15 was studied on a proteomic scale using a 2-D liquid phase separation coupled with MS technology. Whole-cell lysates of E. sibiricum 255–15 grown at 4°C and 25°C were first fractionated according to p I by chromatofocusing (CF), and further separated based on hydrophobicity by nonporous silica RP HPLC (NPS-RP-HPLC) which was on-line coupled with an ESI-TOF MS for intact protein M r measurement and quantitative interlysate comparison. Mass maps were created to visualize the differences in protein expression between different growth temperatures. The differentially expressed proteins were then identified by PMF using a MALDI-TOF MS and peptide sequencing by MS/MS with a MALDI quadrupole IT TOF mass spectrometer (MALDI-QIT-TOF MS). A total of over 500 proteins were detected in this study, of which 256 were identified. Among these proteins 39 were cold acclimation proteins (Caps) that were preferentially or uniquely expressed at 4°C and three were homologous cold shock proteins (Csps). The homologous Csps were found to be similarly expressed at 4°C and 25°C, where these three homologous Csps represent about 10% of the total soluble proteins at both 4°C and 25°C.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55850/1/5221_ftp.pd

Recognition of T-rich single-stranded DNA by the cold shock protein Bs-CspB in solution

Cold shock proteins (CSP) belong to the family of single-stranded nucleic acid binding proteins with OB-fold. CSP are believed to function as ‘RNA chaperones’ and during anti-termination. We determined the solution structure of Bs-CspB bound to the single-stranded DNA (ssDNA) fragment heptathymidine (dT(7)) by NMR spectroscopy. Bs-CspB reveals an almost invariant conformation when bound to dT(7) with only minor reorientations in loop β1–β2 and β3–β4 and of few aromatic side chains involved in base stacking. Binding studies of protein variants and mutated ssDNA demonstrated that Bs-CspB associates with ssDNA at almost diffusion controlled rates and low sequence specificity consistent with its biological function. A variation of the ssDNA affinity is accomplished solely by changes of the dissociation rate. (15)N NMR relaxation and H/D exchange experiments revealed that binding of dT(7) increases the stability of Bs-CspB and reduces the sub-nanosecond dynamics of the entire protein and especially of loop β3–β4

"Ya no quieren hablar sus lenguas" - Der Kontakt des Spanischen mit indigenen Sprachen in León, Mexiko. Eine soziolinguistische Studie

Die vorliegende Arbeit beschäftigt sich mit einer sehr aktuellen Thematik, die bisher in der Hispanistik kaum untersucht wurde, nämlich dem multilateralen Kontakt zwischen dem Spanischen und indigenen Sprachen, die aufgrund von Binnenmigration in einem städtischen Kontext aufeinandertreffen. Die zentralmexikanische Großstadt León de los Aldama (Bundesstaat Guanajuato) stellt keine heimische mesoamerikanische Bevölkerung. Die Präsenz Indigener, die nur 0,24% der Einwohner Leóns bilden, ist dort relativ neu. Daher sind sie in diesem von der hispanophonen Mehrheitsgesellschaft dominierten Umfeld auf Spanischkenntnisse angewiesen, während sie gleichzeitig versuchen, ihre indigene Kultur und Sprache beizubehalten. Die Studie basiert auf einer sechswöchigen Feldforschung, die Sophia Schnuchel im Centro de Desarrollo Indígena Loyola, der interkulturellen Schule Nenemi und der Comunidad Mixteca in León durchführte, wofür 67 Indigene sowie auch Experten befragt wurden. Erhoben wurden 1. Kenntnisse der Sprachgesetzgebung, 2. Selbst- und Fremdeinschätzung der Befragten in Bezug auf ihre Beherrschung von beiden Sprachen, 3. die Gebrauchsdomänen der Idiome, sowie 4. die Sprechereinstellung der Informanten zu ihrer autochthonen Sprache und zum Spanischen

Bilingüismo de indígenas migrantes y desplazamiento de idiomas autóctonos en León, Guanajuato

Abstract: This article illustrates the contact between Spanish and six indigenous languages in the context of internal migration in the Mexican city of León, Guanajuato, by analyzing the language skills of 67 indigenous people, belonging to six ethnic groups, and their level of bilingualism. Results show that oral competence in the vernacular languages is far better than writing skills. Additionally, we observed that adults had a better command of indigenous languages than younger speakers, as well as greater difficulties in using Spanish. Most of the children, in contrast, were bilingual and used Spanish much better than their parents. Also assessed are the contexts in which the different languages are used. The study clearly shows that a situation of diglossia prevails among indigenous peoples living in León.Resumen: El presente artículo trata sobre el contacto del español con seis idiomas indígenas en el contexto de la migración interna en la ciudad de León, Guanajuato. Se analizan los conocimientos lingüísticos de 67 personas indígenas, que pertenecen a seis etnias, y su grado de multilingüismo. Se muestra que la competencia oral en los idiomas indígenas es mejor que la competencia escrita en estos idiomas vernáculos. Además, se observa que los adultos tienen mejores conocimientos de los idiomas indígenas y problemas con el español, mientras que la mayoría de los niños son bilingües y dominan el español mucho mejor que sus padres. También se analizan los contextos en los cuales se usan los idiomas. Se puede constatar que se presenta una situación de diglosia entre los indígenas que viven en León

“La gente se ríe de nosotros porque hablamos otra lengua”: discriminación étnica y lingüística en León, Guanajuato, México

En este artículo los autores presentan los resultados de un estudio de campo llevado a cabo en 2014 en León, Guanajuato, una ciudad industrial del centro norte de México, a partir de las experiencias de 27 individuos pertenecientes a seis pueblos indígenas. Estas comunidades se trasladaron a León, en busca de oportunidades de empleo, durante las últimas cuatro décadas. Se muestran aspectos de las vidas de los migrantes en su nuevo entorno: su vulnerabilidad, el desprecio que experimentan y la discriminación que sufren. Estas personas se encuentran en un espacio intermedio, social y psicológicamente complejo, entre sus culturas tradicionales y el modo de vida de la población mestiza mayoritaria. Aunque hay esfuerzos institucionales para apoyar a los indígenas para que no abandonen su identidad étnica, el menosprecio que experimentan desmotiva el uso de sus lenguas ancestrales.In this article the authors present the results of field work carried out in 2014 in León, Guanajuato, an industrial city of north central Mexico, based on the experiences of 27 individuals pertaining to six indigenous peoples. These communities migrated to León, seeking employment opportunities, during the last four decades. Aspects of the lives of these migrants in their new environment are shown: their vulnerability, the contempt they experience, and the discrimination they suffer. These people find themselves in a middle ground, socially and psychologically complex, between their traditional cultures and the lifestyle of the mestizo majority. In spite of institutional efforts to support these communities in the conservation of their ethnic identity, the disparagement they experience demotivates the use of their ancestral tongues

Quality comparison of a state-of-the-art preparation of a recombinant L-asparaginase derived from Escherichia coli with an alternative asparaginase product.

L-asparaginase (ASNase) is a protein that is essential for the treatment of acute lymphoblastic leukemia (ALL). The main types of ASNase that are clinically used involve native and pegylated Escherichia coli (E. coli)-derived ASNase as well as Erwinia chrysanthemi-derived ASNase. Additionally, a new recombinant E. coli-derived ASNase formulation has received EMA market approval in 2016. In recent years, pegylated ASNase has been preferentially used in high-income countries, which decreased the demand for non-pegylated ASNase. Nevertheless, due to the high cost of pegylated ASNase, non-pegylated ASNase is still widely used in ALL treatment in low- and middle-income countries. As a consequence, the production of ASNase products from low- and middle-income countries increased in order to satisfy the demand worldwide. However, concerns over the quality and efficacy of these products were raised due to less stringent regulatory requirements. In the present study, we compared a recombinant E. coli-derived ASNase marketed in Europe (Spectrila®) with an E. coli-derived ASNase preparation from India (Onconase) marketed in Eastern European countries. To assess the quality attributes of both ASNases, an in-depth characterization was conducted. Enzymatic activity testing revealed a nominal enzymatic activity of almost 100% for Spectrila®, whereas the enzymatic activity for Onconase was only 70%. Spectrila® also showed excellent purity as analyzed by reversed-phase high-pressure liquid chromatography, size exclusion chromatography and capillary zone electrophoresis. Furthermore, levels of process-related impurities were very low for Spectrila®. In comparison, the E. coli DNA content in the Onconase samples was almost 12-fold higher and the content of host cell protein was more than 300-fold higher in the Onconase samples. Our results reveal that Spectrila® met all of the testing parameters, stood out for its excellent quality and, thus, represents a safe treatment option in ALL. These findings are particularly important for low- and middle-income countries, where access to ASNase formulations is limited