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

La importancia del vanadio en los seres vivos

Abstract (The importance of vanadium in living organisms)The discovery of high vanadium concentrations in living organisms and the constant development of bioinorganic chemistry have promoted the interest in understanding the biological role of this metal and its possible applications in medicinal inorganic chemistry. The design of new metal-based drugs depends largely on the physicochemical properties of the metallic center under physiological conditions. In this paper we present a short review on the biological role of vanadium and its function as an active center in certain enzymes, as well as the state-of-the-art of vanadium-based drugs with antifungical, anticarcinogenic and antiobesity properties.ResumenEl descubrimiento de organismos con concentraciones de vanadio superiores a las normales, aunado al desarrollo de la química bioinorgánica, ha despertado interés por entender a fondo las funciones biológicas que este elemento pueda desempeñar y las posibles aplicaciones que los compuestos de coordinación con dicho metal puedan tener en farmacología. El diseño de fármacos basados en metales depende, en gran parte, de las propiedades farmacológicas del centro metálico en el organismo. En este artículo se presenta una breve revisión sobre algunas funciones biológicas del vanadio y su papel en el centro activo de enzimas, así como las últimas investigaciones enfocadas al desarrollo de fármacos basados en vanadio con actividad antifúngica, anticancerígena y antiobesidad

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

Redox-active and DNA-binding coordination complexes of clotrimazole

DNA interactions of anticancer mononuclear Cu2+, Co2+, Zn2+, and Ni2+ complexes with the biologically active ligand clotrimazole (clotri) are reported. To fully characterize DNA binding modes for these complexes of the formulae [M(clotri)2Cl2]·nH2O (1–4), [M(clotri)2Br2]·nH2O (5,6), [M(clotri)3NO3]NO3·nH2O (9), and [M(clotri)3(NO3)2] (10), circular dichroism (CD) and linear dichroism (LD) spectroscopy, UV melting experiments, atomic force microscopy (AFM) and ethidium bromide (EtBr) displacement methods were used. Results indicate mixed electrostatic interactions, possibly through groove binding, that result in accretion and coiling of DNA. Electrochemical studies indicate that the Cu2+ complex 9 readily reduces to the reactive-oxygen-species-generating Cu+, which oxidatively damages DNA. There is a subtle correlation between log P values, calculated electrostatic potentials, and cytotoxicity of the complexes. The extent of cell-nucleus DNA-metal adduct formation in the HeLa cervix-uterine carcinoma cell line does not necessarily correlate with cytotoxicity, indicating that the nature of DNA lesions may be crucial to activity

A remark on the spectrum of the Dirac operator on pseudo-Riemannian spin manifolds

It is proved that the eigenvalues of the Dirac operator on even dimensional space- and time-oriented pseudo-Riemannian spin manifolds lie symmetric to the real and to the imaginary axes, and that the Dirac operator does not have residual spectrum if the associated Riemannian metric is complete. (orig.)Available from TIB Hannover: RR 1596(136) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

CCDC 1820836: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.,Related Article: Rodrigo Castro-Ramírez, Naytzé Ortiz-Pastrana, Ana B. Caballero, Matthew T. Zimmerman, Bradley S. Stadelman, Andrea A. E. Gaertner, Julia L. Brumaghim, Luís Korrodi-Gregório, Ricardo Pérez-Tomás, Patrick Gamez, Norah Barba-Behrens|2018|Dalton Trans.|47|7551|doi:10.1039/C8DT00716

CCDC 1820833: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.,Related Article: Rodrigo Castro-Ramírez, Naytzé Ortiz-Pastrana, Ana B. Caballero, Matthew T. Zimmerman, Bradley S. Stadelman, Andrea A. E. Gaertner, Julia L. Brumaghim, Luís Korrodi-Gregório, Ricardo Pérez-Tomás, Patrick Gamez, Norah Barba-Behrens|2018|Dalton Trans.|47|7551|doi:10.1039/C8DT00716

CCDC 1820834: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.,Related Article: Rodrigo Castro-Ramírez, Naytzé Ortiz-Pastrana, Ana B. Caballero, Matthew T. Zimmerman, Bradley S. Stadelman, Andrea A. E. Gaertner, Julia L. Brumaghim, Luís Korrodi-Gregório, Ricardo Pérez-Tomás, Patrick Gamez, Norah Barba-Behrens|2018|Dalton Trans.|47|7551|doi:10.1039/C8DT00716

CCDC 1820835: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.,Related Article: Rodrigo Castro-Ramírez, Naytzé Ortiz-Pastrana, Ana B. Caballero, Matthew T. Zimmerman, Bradley S. Stadelman, Andrea A. E. Gaertner, Julia L. Brumaghim, Luís Korrodi-Gregório, Ricardo Pérez-Tomás, Patrick Gamez, Norah Barba-Behrens|2018|Dalton Trans.|47|7551|doi:10.1039/C8DT00716