Ferredoxinas

AbstractFerredoxins are soluble proteins that contain iron-sulfur clusters and have low redox potentials. They are present in bacteria, plants, algae and animals and function as electron carriers both in respiration and photosynthesis; and are found as: Type [2Fe-2S], Type [4Fe-4S] and Type [3Fe-4S]. Their ubiquitous presence especially in ancestral organisms has led to the idea that Fe-S proteins are very old proteins that appeared in early stages of evolution. They form a particularly versatile and useful, as well as modular and simple group of metalloproteins that achieve a vast number of functions. Here the characteristics of the different types of ferredoxins and their biological functions are discussed, together with an overview of the spectroscopic techniques employed for their study. Additionally, the result of kinetic studies of ferredoxins and inorganic compounds to learn about the reaction mechanisms are included

Metalochaperonas: escoltas personales en el tráfico intracelular de iones metálicos

AbstractMetallochaperones are proteins that specifically bind metal ions with high affinity and selectivity to deliver them to target proteins, acting in the intracellular trafficking of metal ions to guide and protect them toward their fnal destination, and consequently, protecting cell against free metal toxicity. Knowledge in this area is limited, nevertheless, some metallochaperones have been properly identified and are well characterized for their structure, their roles and the mechanisms involved in the molecular recognition and metal ion transfer between the metallochaperone and the target protein, therefore allowing a proper understanding of the way these macromolecules function. Metallochaperones of copper are the most studied metallochaperones and more information about them is found in the literature. However, information about those employed for other metals is also found, particularly those employed for delivering iron, followed by those employed for nickel, only scarce information is found on those related with zinc and even less for other metals. In this manuscript, a general view of information found in literature about the functions of metallochaperones involved in the trafficking of metal ion or assembly of metal centers and their mechanisms is given, with the aim of provide current educational material for bioinorganic undergraduate teachers and students about an emerging subject hard to find in bioinorganic textbooks.ResumenLas metalochaperonas son proteínas que están diseñadas para unir metales específicos con gran afinidad y selectividad para entregarlos a proteínas que lo requieren en su estructura. El conocimiento en esta área es limitado; sin embargo, existen algunos casos bien identificados y caracterizados que permiten comprender cómo funcionan estas macromoléculas, cuál es su función y cuáles son los mecanismos involucrados en el reconocimiento molecular entre la metalochaperona y la proteína blanco, y cómo ocurre la transferencia del metal para realizar la entrega en el sitio adecuado. Las metalochaperonas de cobre son las más estudiadas y, por tanto, existe más información sobre ellas en la literatura. Sin embargo, existe también información sobre metalochaperonas para otros metales, particularmente aquellas que se encargan de la entrega de hierro, seguidas de las de níquel, solo escasa información acerca de las de zinc e incluso menos de otros metales. Esta revisión pretende documentar esos casos conocidos para proporcionar una visión general sobre las funciones de las metalochaperonas en el tráfico intracelular de metales o en el ensamblaje de centros metálicos y los mecanismos mediante los cuales trabajan, con el objetivo de generar material educativo actual para profesores y estudiantes de bioinorgánica acerca de un tema nuevo que es difícil de encontrar en los libros de texto de bioinorgánica

Normal solution and transport coefficients to the Enskog-Landau kinetic equation for a two-component system of charged hard spheres. The Chapman-Enskog method

An Enskog-Landau kinetic equation for a many-component system of charged hard spheres is proposed. It has been obtained from the Liouville equation with modified boundary conditions by the method of nonequilibrium statistical operator. On the basis of this equation the normal solutions and transport coefficients such as bulk kappa and shear eta viscosities, thermal conductivity lambda, mutual diffusion D^{\alpha\beta} and thermal diffusion D_T^\alpha have been obtained for a binary mixture in the first approximation using the Chapman-Enskog method. Numerical calculations of all transport coefficients for mixtures Ar-Kr, Ar-Xe, Kr-Xe with different concentrations of compounds have been evaluated for the cases of absence and presence of long-range Coulomb interactions. The results are compared with those obtained from other theories and experiment.Comment: 24 LaTeX209 pages, 3 EPS figures (4 files). To be published in Physica

2-(1,3-Thia­zol-4-yl)benzimidazolium nitrate monohydrate

In the title compound, C10H8N3S+·NO3 −·H2O, one of the N atoms of the benzimidazole unit is protonated, unlike than that in the thia­zole group. This protonation leads to equalization of the bond angles at the two N atoms of the benzimidazole group. The benzimidazole and thia­zole systems are almost coplanar, forming a dihedral angle of 0.5 (2)°. In the crystal, the nitrate anion and water mol­ecule bridge the thia­bendazolium cations through N—H⋯O and O—H⋯O hydrogen bonds, leading to a supra­molecular network based on an infinite one-dimensional chain using [001] as base vector

Trans-Atlantic exchanges have shaped the population structure of the Lyme disease agent Borrelia burgdorferi sensu stricto

The origin and population structure of Borrelia burgdorferi sensu stricto (s.s.), the agent of Lyme disease, remain obscure. This tick-transmitted bacterial species occurs in both North America and Europe. We sequenced 17 European isolates (representing the most frequently found sequence types in Europe) and compared these with 17 North American strains. We show that trans-Atlantic exchanges have occurred in the evolutionary history of this species and that a European origin of B. burgdorferi s. s. is marginally more likely than a USA origin. The data further suggest that some European human patients may have acquired their infection in North America. We found three distinct genetically differentiated groups: i) the outgroup species Borrelia bissettii, ii) two divergent strains from Europe, and iii) a group composed of strains from both the USA and Europe. Phylogenetic analysis indicated that different genotypes were likely to have been introduced several times into the same area. Our results demonstrate that irrespective of whether B. burgdorferi s. s. originated in Europe or the USA, later trans-Atlantic exchange(s) have occurred and have shaped the population structure of this genospecies. This study clearly shows the utility of next generation sequencing to obtain a better understanding of the phylogeography of this bacterial species

Infographic. How does exercise treatment compare with antihypertensive medications?

High systolic blood pressure (SBP) remains the major cause of premature death globally despite advances in pharmacological treatment.1 2 The global direct medical costs associated with hypertension treatment are estimated at $370 billion/year worldwide, with the healthcare savings from effective management of this condition projected at about$100 billion/year.3 Unfortunately, relatively little attention is given to non-pharmacological strategies, including structured exercise interventions. A recent network meta-analysis of randomised controlled trials (RCTs) published in the BJSM4 aimed to compare the effects of exercise interventions and medications on SBP. We highlight the key findings of this network meta-analysis that are particularly relevant for clinical practice and health policy.Sin financiación12.022 JCR (2019) Q1, 1/85 Sport Sciences3.712 SJR (2019) Q1, 48/2754 Medicine (miscellaneous), 1/284 Orthopedics and Sports Medicine, 1/207 Physical Therapy, Sports Therapy and Rehabilitation, 2/125 Sports ScienceNo data IDR 2019UE

Earth and Terrestrial Planet Formation

The growth and composition of Earth is a direct consequence of planet formation throughout the Solar System. We discuss the known history of the Solar System, the proposed stages of growth and how the early stages of planet formation may be dominated by pebble growth processes. Pebbles are small bodies whose strong interactions with the nebula gas lead to remarkable new accretion mechanisms for the formation of planetesimals and the growth of planetary embryos. Many of the popular models for the later stages of planet formation are presented. The classical models with the giant planets on fixed orbits are not consistent with the known history of the Solar System, fail to create a high Earth/Mars mass ratio, and, in many cases, are also internally inconsistent. The successful Grand Tack model creates a small Mars, a wet Earth, a realistic asteroid belt and the mass-orbit structure of the terrestrial planets. In the Grand Tack scenario, growth curves for Earth most closely match a Weibull model. The feeding zones, which determine the compositions of Earth and Venus follow a particular pattern determined by Jupiter, while the feeding zones of Mars and Theia, the last giant impactor on Earth, appear to randomly sample the terrestrial disk. The late accreted mass samples the disk nearly evenly.Comment: Accepted for publication in Early Earth an AGU Monograph edited by James Badro and Michael J. Walte

Zinc associated nanomaterials and their intervention in emerging respiratory viruses:Journey to the field of biomedicine and biomaterials

Respiratory viruses represent a severe public health risk worldwide, and the research contribution to tackle the current pandemic caused by the SARS-CoV-2 is one of the main targets among the scientific community. In this regard, experts from different fields have gathered to confront this catastrophic pandemic. This review illustrates how nanotechnology intervention could be valuable in solving this difficult situation, and the state of the art of Zn-based nanostructures are discussed in detail. For virus detection, learning from the experience of other respiratory viruses such as influenza, the potential use of Zn nanomaterials as suitable sensing platforms to recognize the S1 spike protein in SARS-CoV-2 are shown. Furthermore, a discussion about the antiviral mechanisms reported for ZnO nanostructures is included, which can help develop surface disinfectants and protective coatings. At the same time, the properties of Zn-based materials as supplements for reducing viral activity and the recovery of infected patients are illustrated. Within the scope of noble adjuvants to improve the immune response, the ZnO NPs properties as immunomodulators are explained, and potential prototypes of nanoengineered particles with metallic cations (like Zn(2+)) are suggested. Therefore, using Zn-associated nanomaterials from detection to disinfection, supplementation, and immunomodulation opens a wide area of opportunities to combat these emerging respiratory viruses. Finally, the attractive properties of these nanomaterials can be extrapolated to new clinical challenges

Zinc associated nanomaterials and their intervention in emerging respiratory viruses: Journey to the field of biomedicine and biomaterials.

Respiratory viruses represent a severe public health risk worldwide, and the research contribution to tackle the current pandemic caused by the SARS-CoV-2 is one of the main targets among the scientific community. In this regard, experts from different fields have gathered to confront this catastrophic pandemic. This review illustrates how nanotechnology intervention could be valuable in solving this difficult situation, and the state of the art of Zn-based nanostructures are discussed in detail. For virus detection, learning from the experience of other respiratory viruses such as influenza, the potential use of Zn nanomaterials as suitable sensing platforms to recognize the S1 spike protein in SARS-CoV-2 are shown. Furthermore, a discussion about the antiviral mechanisms reported for ZnO nanostructures is included, which can help develop surface disinfectants and protective coatings. At the same time, the properties of Zn-based materials as supplements for reducing viral activity and the recovery of infected patients are illustrated. Within the scope of noble adjuvants to improve the immune response, the ZnO NPs properties as immunomodulators are explained, and potential prototypes of nanoengineered particles with metallic cations (like Zn2+) are suggested. Therefore, using Zn-associated nanomaterials from detection to disinfection, supplementation, and immunomodulation opens a wide area of opportunities to combat these emerging respiratory viruses. Finally, the attractive properties of these nanomaterials can be extrapolated to new clinical challenges

Cobalt(II) Coordination Compounds of Ethyl 4-Methyl-5-Imidazolecarboxylate: Chemical and Biochemical Characterization on Photosynthesis and Seed Germination

In this work we present the synthesis, structural and spectroscopic characterization of Co(2+) coordination compounds with ethyl 4-methyl-5-imidazolecarboxylate (emizco). The effects of emizco, the metal salts CoCl(2).6H(2)O, CoBr(2), Co(NO(3))(2).6H(2)O and their metal coordination compounds [Co(emizco)(2)Cl(2)], [Co(emizco)(2) Br(2)].H(2)O, [Co(emizco)(2) (H(2)O)(2)(NO(2))(2).2H(2)O were evaluated on photosynthesis in spinach chloroplasts. Seed germination and seedling growth of the monocotyledonous species Lolium multiflorum and Triticum aestivum and the dicotyledonous species Trifolium alexandrinum and Physalis ixocarpa were also assayed under the effect of the compounds and salts. The results showed that cobalt(II) salts and their emizco coordination compounds inhibit photosynthetic electron flow and ATP-synthesis, behaving as Hill reaction inhibitors. Coordination compounds are more potent inhibitors than the salts. It was found that the salts target is at the b(6)f level while the complexes targets are at Q(B)(D1)-protein and b(6)f level. The Q(B) inhibition site was confirmed by variable chlorophyll a fluorescence yield. On the other hand, emizco inhibits seed germination, root and shoot development, in both weed and crop species. Cobalt(II) coordination compounds are the most effective photosynthesis inhibitors, but they are less potent than emizco in germination and seedling growth, while the metal salts are the least active of all