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Chávez M, Fernandez-Merino Á, Del Caño R, Sánchez-Obrero G, Madueño R, Blázquez M, Pineda T. Behind the Optimization of the Sensor Film: Bioconjugation of Triangular Gold Nanoparticles with Hemoproteins for Sensitivity Enhancement of Enzymatic Biosensors. Biosensors (Basel) 2023; 13:bios13040467. [PMID: 37185542 PMCID: PMC10136871 DOI: 10.3390/bios13040467] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/01/2023] [Accepted: 04/07/2023] [Indexed: 05/17/2023]
Abstract
Electrochemical biosensors are widely used in a multitude of applications, such as medical, nutrition, research, among other fields. These sensors have been historically used and have not undergone many changes in terms of the involved electrochemical processes. In this work, we propose a new approach on the immobilization and enhancement of the electrochemical properties of the sensing layers through the control and bioconjugation of hemoproteins (hemoglobin, myoglobin, and cytochrome C) on anisotropic gold nanoparticles (gold nanotriangles (AuNTs)). The hemeproteins and the AuNTs are mixed in a solution, resulting in stable bioconjugates that are deposited onto the electrode surface to obtain the biosensors. All the systems proposed herein exhibited direct well-defined redox responses, highlighting the key role of the AuNTs acting as mediators of such electron transfers. Several protein layers surrounding the AuNTs are electroactive, as demonstrated from the charge measured by cyclic voltammetry. The retention of the stability of the hemeproteins once they are part of the bioconjugates is evidenced towards the electrocatalytic reduction of hydrogen peroxide, oxygen, and nitrite. The parameters obtained for the proposed biosensors are similar or even lower than those previously reported for similar systems based on nanomaterials, and they exhibit attractive properties that make them potential candidates for the latest developments in the field of sensing devices.
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Affiliation(s)
- Miriam Chávez
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Chemistry for Energy and Environment, University of Cordoba, Campus Rabanales, Ed. Marie Curie, E-14014 Córdoba, Spain
| | - Ángela Fernandez-Merino
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Chemistry for Energy and Environment, University of Cordoba, Campus Rabanales, Ed. Marie Curie, E-14014 Córdoba, Spain
| | - Rafael Del Caño
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Chemistry for Energy and Environment, University of Cordoba, Campus Rabanales, Ed. Marie Curie, E-14014 Córdoba, Spain
| | - Guadalupe Sánchez-Obrero
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Chemistry for Energy and Environment, University of Cordoba, Campus Rabanales, Ed. Marie Curie, E-14014 Córdoba, Spain
| | - Rafael Madueño
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Chemistry for Energy and Environment, University of Cordoba, Campus Rabanales, Ed. Marie Curie, E-14014 Córdoba, Spain
| | - Manuel Blázquez
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Chemistry for Energy and Environment, University of Cordoba, Campus Rabanales, Ed. Marie Curie, E-14014 Córdoba, Spain
| | - Teresa Pineda
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Chemistry for Energy and Environment, University of Cordoba, Campus Rabanales, Ed. Marie Curie, E-14014 Córdoba, Spain
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Chávez M, Sánchez-Obrero G, Madueño R, Manuel Sevilla J, Blázquez M, Pineda T. Effects of the potential and the electrolyte nature in the integrity of the O-(2-Mercaptoethyl)-O′-methyl-hexa(ethylene glycol) self-assembled monolayer by electrochemical impedance spectroscopy. J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.116996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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3
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Chávez M, Fuentes-Rodríguez L, Sánchez-Obrero G, Madueño R, Sevilla JM, Blázquez M, Pineda T. Characterization of self-assembled Bis[2-(2-bromoisobutyryloxy) undecyl] disulphide (DTBU) on gold surfaces suitable for use in surface-initiated atom transfer radical polymerization (SI-ATRP). J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.116515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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4
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Chávez M, Sánchez-Obrero G, Madueño R, Sevilla JM, Blázquez M, Pineda T. Electrochemical evaluation of the grafting density of self-assembled monolayers of polyethylene glycol of different chain lengths formed by the grafting to approach under conditions close to the cloud point. J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.116294] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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5
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Delbes G, Blázquez M, Fernandino JI, Grigorova P, Hales BF, Metcalfe C, Navarro-Martín L, Parent L, Robaire B, Rwigemera A, Van Der Kraak G, Wade M, Marlatt V. Effects of endocrine disrupting chemicals on gonad development: Mechanistic insights from fish and mammals. Environ Res 2022; 204:112040. [PMID: 34509487 DOI: 10.1016/j.envres.2021.112040] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/03/2021] [Accepted: 09/08/2021] [Indexed: 06/13/2023]
Abstract
Over the past century, evidence has emerged that endocrine disrupting chemicals (EDCs) have an impact on reproductive health. An increased frequency of reproductive disorders has been observed worldwide in both wildlife and humans that is correlated with accidental exposures to EDCs and their increased production. Epidemiological and experimental studies have highlighted the consequences of early exposures and the existence of key windows of sensitivity during development. Such early in life exposures can have an immediate impact on gonadal and reproductive tract development, as well as on long-term reproductive health in both males and females. Traditionally, EDCs were thought to exert their effects by modifying the endocrine pathways controlling reproduction. Advances in knowledge of the mechanisms regulating sex determination, differentiation and gonadal development in fish and rodents have led to a better understanding of the molecular mechanisms underlying the effects of early exposure to EDCs on reproduction. In this manuscript, we review the key developmental stages sensitive to EDCs and the state of knowledge on the mechanisms by which model EDCs affect these processes, based on the roadmap of gonad development specific to fish and mammals.
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Affiliation(s)
- G Delbes
- Centre Armand Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Laval, Canada.
| | - M Blázquez
- Institute of Marine Sciences (ICM-CSIC), Barcelona, Spain
| | - J I Fernandino
- Instituto Tecnológico de Chascomús (CONICET-UNSAM), Chascomús, Argentina
| | | | - B F Hales
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - C Metcalfe
- School of Environment, Trent University, Trent, Canada
| | - L Navarro-Martín
- Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain
| | - L Parent
- Université TELUQ, Montréal, Canada
| | - B Robaire
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada; Department of Obstetrics and Gynecology, McGill University, Montreal, Canada
| | - A Rwigemera
- Centre Armand Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Laval, Canada
| | - G Van Der Kraak
- Department of Integrative Biology, University of Guelph, Guelph, Canada
| | - M Wade
- Environmental Health Science & Research Bureau, Health Canada, Ottawa, Canada
| | - V Marlatt
- Department of Biological Sciences, Simon Fraser University, Burnaby, Canada
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6
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Hernández-Moreno D, Blázquez M, Navas JM, Fernández-Cruz ML. Fish cell lines as screening tools to predict acute toxicity to fish of biocidal active substances and their relevant environmental metabolites. Aquat Toxicol 2022; 242:106020. [PMID: 34844051 DOI: 10.1016/j.aquatox.2021.106020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 11/05/2021] [Accepted: 11/07/2021] [Indexed: 06/13/2023]
Abstract
Biocidal substances and their environmental relevant metabolites are highly toxic for fish. However, an important scarcity of toxicity data for metabolites is recognised. This article provides new data about the toxicity to fish of these compounds and evaluates the potential use of fish cell lines as screening tools to assess the acute toxicity of these compounds in fish. To this aim, acute toxicity of 7 substances was tested in Oncorhynchus mykiss (OECD TG203) and cytotoxicity of 16 substances was assessed in fish cell lines from two species; Poeciliopsis lucida (PLHC-1) and O. mykiss (RTH-149, RTG-2 and RTgill-W1) performing three cytotoxicity tests: Alamar-Blue, 5-carboxyfluorescein diacetate, acetoxymethyl ester and Neutral Red Uptake. Additionally, in vitro and in vivo data from the LIFE-COMBASE database were included in a dataset finally comprising 33 biocides and 14 metabolites. Hazard data were categorized into 4 toxicity groups, according to the intervals established in Regulation (EC) 1272/2008. Finally, the Spearman correlation test was performed and coincidences between in vitro-in vivo data established. In vitro and in vivo results revealed a high positive correlation, with a complete coincidence for 56.5% of the substances, a 2% of false positives (non-toxic in vivo) and a 13% of false negatives (toxic in vivo) for the 4 toxicity categories. However, when results were grouped in toxic or non-toxic coincidence was obtained for 85% of the substances. In conclusion, although fish denote a greater sensitivity, the use of at least two fish cell lines and three cytotoxicity endpoints appear to be valid approaches for fish acute toxicity screening of biocides and their metabolites.
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Affiliation(s)
- D Hernández-Moreno
- National Institute of Agriculture and Food Research and Technology (INIA), Spanish National Research Council (CSIC), Department of Environment and Agronomy, Carretera de la Coruña Km 7 Madrid, Spain
| | - M Blázquez
- Inkoa Sistemas S.L. Polígono Industrial Ribera de Axpe, 11, Erandio, Vizcaya, Spain; CBET Research Group, Department of Zoology and Animal Cell Biology, Faculty of Science and Technology and Research Centre for Experimental Marine Biology and Biotechnology PIE, University of the Basque Country UPV/EHU, Basque Country, Spain
| | - J M Navas
- National Institute of Agriculture and Food Research and Technology (INIA), Spanish National Research Council (CSIC), Department of Environment and Agronomy, Carretera de la Coruña Km 7 Madrid, Spain
| | - M L Fernández-Cruz
- National Institute of Agriculture and Food Research and Technology (INIA), Spanish National Research Council (CSIC), Department of Environment and Agronomy, Carretera de la Coruña Km 7 Madrid, Spain.
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7
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Chávez M, Fernández-Merino Á, Sánchez-Obrero G, Madueño R, Sevilla JM, Blázquez M, Pineda T. Distinct thermoresponsive behaviour of oligo- and poly-ethylene glycol protected gold nanoparticles in concentrated salt solutions. Nanoscale Adv 2021; 3:4767-4779. [PMID: 36134318 PMCID: PMC9417796 DOI: 10.1039/d1na00392e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 07/02/2021] [Indexed: 05/09/2023]
Abstract
In this work, the methoxy terminated oligo- and polyethylene glycol of different chain lengths (EGn, n = 7, 18, 45 and 136) is grafted on AuNP surfaces under conditions where they attain maximum grafting densities. These EGn-AuNPs gain stability relative to the pristine c-AuNPs in aqueous solutions and in a wide temperature interval and they form stable suspensions in solutions of high NaCl concentrations. To show the thermoresponsive properties of these EGn-AuNPs, temperature titration experiments are carried out in the presence of increasing amounts of salts. The concentrations of NaCl are chosen by checking the stability of EGn-AuNPs at room temperature and choosing the highest concentrations that allow them to form stable suspensions. The analysis of the temperature titration experiments monitored by UV-visible spectroscopy and dynamic light scattering allows us to establish the existence of transitions from individual to assembled nanoparticles, the reversibility of the temperature transitions and hysteretic behaviour in these systems. While EG7-AuNPs only show reversible temperature transitions in the presence of 5 mM NaCl, EG18-AuNPs do up to 1 M NaCl, becoming only partially reversible in 2 M NaCl. The titrations of EG45-AuNPs in 3 and 5 M NaCl show irreversible temperature transitions. Finally, EG136-AuNPs present a complex and interesting behaviour with two temperature transitions, the first one showing hysteresis and the second being reversible.
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Affiliation(s)
- Miriam Chávez
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales Ed. Marie Curie 2a Planta E-14014 Córdoba Spain
| | - Ángela Fernández-Merino
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales Ed. Marie Curie 2a Planta E-14014 Córdoba Spain
| | - Guadalupe Sánchez-Obrero
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales Ed. Marie Curie 2a Planta E-14014 Córdoba Spain
| | - Rafael Madueño
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales Ed. Marie Curie 2a Planta E-14014 Córdoba Spain
| | - José Manuel Sevilla
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales Ed. Marie Curie 2a Planta E-14014 Córdoba Spain
| | - Manuel Blázquez
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales Ed. Marie Curie 2a Planta E-14014 Córdoba Spain
| | - Teresa Pineda
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales Ed. Marie Curie 2a Planta E-14014 Córdoba Spain
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Marzo M, Lavado GJ, Como F, Toropova AP, Toropov AA, Baderna D, Cappelli C, Lombardo A, Toma C, Blázquez M, Benfenati E. QSAR models for biocides: The example of the prediction of Daphnia magna acute toxicity. SAR QSAR Environ Res 2020; 31:227-243. [PMID: 31941347 DOI: 10.1080/1062936x.2019.1709221] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 12/22/2019] [Indexed: 06/10/2023]
Abstract
Biocides are multi-component products used to control undesired and harmful organisms able to affect human or animal health or to damage natural and manufactured products. Because of their widespread use, aquatic and terrestrial ecosystems could be contaminated by biocides. The environmental impact of biocides is evaluated through eco-toxicological studies with model organisms of terrestrial and aquatic ecosystems. We focused on the development of in silico models for the evaluation of the acute toxicity (EC50) of a set of biocides collected from different sources on the freshwater crustacean Daphnia magna, one of the most widely used model organisms in aquatic toxicology. Toxicological data specific for biocides are limited, so we developed three models for daphnid toxicity using different strategies (linear regression, random forest, Monte Carlo (CORAL)) to overcome this limitation. All models gave satisfactory results in our datasets: the random forest model showed the best results with a determination coefficient r2 = 0.97 and 0.89, respectively, for the training (TS) and the validation sets (VS) while linear regression model and the CORAL model had similar but lower performance (r2 = 0.83 and 0.75, respectively, for TS and VS in the linear regression model and r2 = 0.74 and 0.75 for the CORAL model).
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Affiliation(s)
- M Marzo
- Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCSS, Milano, Italy
| | - G J Lavado
- Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCSS, Milano, Italy
| | - F Como
- REACHUP srl, Milano, Italy
| | - A P Toropova
- Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCSS, Milano, Italy
| | - A A Toropov
- Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCSS, Milano, Italy
| | - D Baderna
- Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCSS, Milano, Italy
| | - C Cappelli
- Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCSS, Milano, Italy
| | - A Lombardo
- Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCSS, Milano, Italy
| | - C Toma
- Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCSS, Milano, Italy
| | - M Blázquez
- Inkoa Sistemas S.L., Bilbao, Spain
- CBET Research Group, Department of Zoology and Animal Cell Biology; Faculty of Science and Technology and Research Centre for Experimental Marine Biology and Biotechnology PiE, University of the Basque Country UPV/EHU, Bilbao, Spain
| | - E Benfenati
- Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCSS, Milano, Italy
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Del Caño R, Gisbert-González JM, González-Rodríguez J, Sánchez-Obrero G, Madueño R, Blázquez M, Pineda T. Effective replacement of cetyltrimethylammonium bromide (CTAB) by mercaptoalkanoic acids on gold nanorod (AuNR) surfaces in aqueous solutions. Nanoscale 2020; 12:658-668. [PMID: 31829396 DOI: 10.1039/c9nr09137h] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The highly packed cetyltrimethylammonium bromide (CTAB) bilayer built up on the surface of gold nanorods (AuNRs) when synthesized by the seed-mediated procedure hampers the complete ligand exchange under experimental conditions that preserves the stability of the dispersions. In the present work, a ligand exchange protocol by using carboxy-terminated alkanethiols of different chain lengths by means of a green approach that uses only aqueous solutions is presented. The protocol is based on the knowledge of the stability in the aqueous solution of both the starting CTAB-AuNRs and the final products that help in the choice of the experimental conditions used for ligand exchange. The characterization of the CTAB protective layer as well as the study of its colloidal stability in solution has helped us to design an appropriate methodology. Cyclic voltammetry of CTAB-AuNRs demonstrates the high stability of the bilayer showing the existence of a two-dimensional phase transition from a highly ordered to a less organized phase. Other techniques such as XPS, FT-IR and Raman spectroscopy provide information about the structure of the layer and UV-visible-NIR spectroscopy establishes the stability conditions in aqueous solution. We have chosen an exchange procedure for 11-mercaptoundecanoic acid (MUA) and 16-mercaptohexadecanoic acid (MHDA) based on a one-pot methodology under conditions where all the species involved are stable. The protocol, however, can be extended to different chemical functionalities that are considered useful to be applied in living systems. Under these conditions the complete exchange of CTAB by the mercaptoderivatives was successful as demonstrated by the different characterization techniques used: UV-visible-NIR, FT-IR, Raman, XPS spectroscopy, cyclic voltammetry and transmission electron microscopy (TEM).
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Affiliation(s)
- Rafael Del Caño
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain.
| | - Jose M Gisbert-González
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain.
| | - Jose González-Rodríguez
- School of Chemistry, College of Science, University of Lincoln, Brayford Pool, Lincoln LN67TS, UK
| | - Guadalupe Sánchez-Obrero
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain.
| | - Rafael Madueño
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain.
| | - Manuel Blázquez
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain.
| | - Teresa Pineda
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain.
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Blázquez M, Fernández-Cruz M, Gajewicz A, Puzyn T, Benfenati E. On the uses of predictive toxicology to approve the use of engineered nanomaterials as biocidal active substances under the Biocidal Products Regulation. ACTA ACUST UNITED AC 2019. [DOI: 10.1088/1757-899x/499/1/012007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Sánchez-Obrero G, Chávez M, Madueño R, Blázquez M, Pineda T, López-Romero JM, Sarabia F, Hierrezuelo J, Contreras-Caceres R. Study of the self-assembly process of an oligo(ethylene glycol)-thioacetyl substituted theophylline (THEO) on gold substrates. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2018.07.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Del Caño R, Mateus L, Sánchez-Obrero G, Manuel Sevilla J, Madueño R, Blázquez M, Pineda T. Hemoglobin becomes electroactive upon interaction with surface-protected Au nanoparticles. Talanta 2018; 176:667-673. [PMID: 28917805 DOI: 10.1016/j.talanta.2017.08.090] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/24/2017] [Accepted: 08/29/2017] [Indexed: 10/18/2022]
Abstract
In this work, we report on the electrochemical behavior of bioconjugates prepared with gold nanoparticles (AuNP) capped with three different molecular layers (citrate anions, 6-mercaptopurine and ω-mercaptoundecanoic acid) and the protein hemoglobin (Hb). Freshly formed bioconjugates are deposited on a glassy carbon electrode and assayed for electroactivity. A pair of redox peaks with formal potential at -0.37V is obtained, in contrast with the free Hb protein that is inactive on the glassy carbon substrate. The redox response is typical for quasi-reversible processes allowing the determination of the electron transfer rate constant for the three bioconjugates. Additional evidence of the structural integrity of protein upon forming the bioconjugate is obtained by monitoring the electrochemical response of the Hb heme Fe(III)/Fe(II) redox couple as a function of solution pH. Moreover, the Hb forming the protein corona around the AuNPs show good electrocatalytic activity for the reduction of hydrogen peroxide and oxygen. It has been found that only the first layer of Hb surrounding the AuNPs are electroactive, although some part of the second layer also contribute, pointing to the role of the AuNP in the electrochemical response.
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Affiliation(s)
- Rafael Del Caño
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain
| | - Lucia Mateus
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain
| | - Guadalupe Sánchez-Obrero
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain
| | - José Manuel Sevilla
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain
| | - Rafael Madueño
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain
| | - Manuel Blázquez
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain
| | - Teresa Pineda
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain.
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13
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Del Caño R, Mateus L, Sánchez-Obrero G, Sevilla JM, Madueño R, Blázquez M, Pineda T. Hemoglobin bioconjugates with surface-protected gold nanoparticles in aqueous media: The stability depends on solution pH and protein properties. J Colloid Interface Sci 2017; 505:1165-1171. [PMID: 28715860 DOI: 10.1016/j.jcis.2017.07.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 06/29/2017] [Accepted: 07/02/2017] [Indexed: 12/26/2022]
Abstract
The identification of the factors that dictate the formation and physicochemical properties of protein-nanomaterial bioconjugates are important to understand their behavior in biological systems. The present work deals with the formation and characterization of bioconjugates made of the protein hemoglobin (Hb) and gold nanoparticles (AuNP) capped with three different molecular layers (citrate anions (c), 6-mercaptopurine (MP) and ω-mercaptoundecanoic acid (MUA)). The main focus is on the behavior of the bioconjugates in aqueous buffered solutions in a wide pH range. The stability of the bioconjugates have been studied by UV-visible spectroscopy by following the changes in the localized surface resonance plasmon band (LSRP), Dynamic light scattering (DLS) and zeta-potential pH titrations. It has been found that they are stable in neutral and alkaline solutions and, at pH lower than the protein isoelectric point, aggregation takes place. Although the surface chemical properties of the AuNPs confer different properties in respect to colloidal stability, once the bioconjugates are formed their properties are dictated by the Hb protein corona. The protein secondary structure, as analyzed by Attenuated total reflectance infrared (ATR-IR) spectroscopy, seems to be maintained under the conditions of colloidal stability but some small changes in protein conformation take place when the bioconjugates aggregate. These findings highlight the importance to keep the protein structure upon interaction with nanomaterials to drive the stability of the bioconjugates.
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Affiliation(s)
- Rafael Del Caño
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain
| | - Lucia Mateus
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain
| | - Guadalupe Sánchez-Obrero
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain
| | - José Manuel Sevilla
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain
| | - Rafael Madueño
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain
| | - Manuel Blázquez
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain
| | - Teresa Pineda
- Department of Physical Chemistry and Applied Thermodynamics, Institute of Fine Chemistry and Nanochemistry, University of Cordoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Spain.
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Solé M, Mañanós E, Blázquez M. Vitellogenin, sex steroid levels and gonadal biomarkers in wild Solea solea and Solea senegalensis from NW Mediterranean fishing grounds. Mar Environ Res 2016; 117:63-74. [PMID: 27088613 DOI: 10.1016/j.marenvres.2016.03.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 03/23/2016] [Accepted: 03/29/2016] [Indexed: 06/05/2023]
Abstract
Specimens of Solea solea and Solea senegalenesis at different developmental stages were obtained from seven fishing grounds along the NW Mediterranean. Gonad development in males was classified into five stages, from early spermatogenesis to recovery, while four stages were considered in females, from growth to maturation. Vitellogenin (VTG) and sex steroid levels including an estrogen (estradiol, E2), two androgens (testosterone, T and 11-ketotestosterone, 11KT) and a progestin (17,20β-dihydroxy pregn-4-en-3-one, 17,20β-P or maturation inducing steroid, MIS) were analysed in plasma. Their levels were more clearly related to the developmental stage of the gonads than to the sampling site characteristics. In addition, enzyme activities in gonads, such as acetylcholinesterase (AChE) and carboxylesterase (CbE) were gender-dependent and higher in males than in females. Gonadal glutathione S-transferase (GST) activity was enhanced in the most anthropogenic impacted sites. VTG was absent in males and very low or undetectable in immature females, while mature females exhibited high VTG levels, clearly related to the gonado-somatic index. Sex steroid levels (ng/ml) varied in males and females regardless of the species. E2 levels in females ranged from 0.22 to 6.98 while in males ranged from 0.11 to 0.27. T varied from 0.12 to 0.93 in females and from 0.56 to 1.36 in males, while 11KT in females fluctuated from 0.03 to 0.57 and from 0.26 to 6.42 in males. Similarly, MIS in females ranged from 0.75 to 3.71 and from 1.12 to 5.61 in males. The lack of endocrine disturbances was confirmed by histological examination of the gonads. This study informs on basal sex hormone levels and enzyme activities during gonadal maturation of wild Solea spp. that can be useful in the identification and further remediation of possible pollution events.
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Affiliation(s)
- M Solé
- Institut de Ciencies del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta 37-49, 08003, Barcelona, Spain.
| | - E Mañanós
- Instituto de Acuicultura Torre la Sal (IATS-CSIC), Ribera de Cabanes s/n, 12595, Torre de la Sal, Castellón, Spain
| | - M Blázquez
- Institut de Ciencies del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta 37-49, 08003, Barcelona, Spain
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15
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Fernandes D, Dimastrogiovanni G, Blázquez M, Porte C. Metabolism of the polycyclic musk Galaxolide and its interference with endogenous and xenobiotic metabolizing enzymes in the sea bass (Dicentrarchus labrax). Comp Biochem Physiol A Mol Integr Physiol 2012. [DOI: 10.1016/j.cbpa.2012.05.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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Gonzalez-Rodríguez J, Sevilla JM, Pineda T, Blázquez M. A comparative study of the electrochemical properties of vitamin B-6 related compounds at physiological pH. RUSS J ELECTROCHEM+ 2011. [DOI: 10.1134/s102319351107007x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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García Raya D, Madueño R, Blázquez M, Pineda T. Formation of a 1,8-octanedithiol self-assembled monolayer on Au(111) prepared in a lyotropic liquid-crystalline medium. Langmuir 2010; 26:11790-11796. [PMID: 20578682 DOI: 10.1021/la101976x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A characterization of the 1,8-octanedithiol (ODT) self-assembled monolayer (SAM) formed from a Triton X-100 lyotropic medium has been conducted by electrochemical techniques. It is found that an ODT layer of standing-up molecules is obtained at short modification time without removing oxygen from the medium. The electrochemical study shows that the ODT layer formed after 15 min of modification time has similar electron-transfer blocking properties to the layers formed from organic solvents at much longer modification times. On the basis of XPS data, it is demonstrated that the inability to bind gold nanoparticles (AuNPs) is due to the presence of extra ODT molecules either interdigited or on top of the layer. Treatment consisting of an acid washing step following the formation of the ODT-Au(111) SAM produces a layer that is able to attach AuNPs as demonstrated by electrochemical techniques and atomic force microscopy (AFM) images.
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Affiliation(s)
- Daniel García Raya
- Departamento de Química Física y Termodinámica Aplicada, Universidad de Córdoba, Campus de Rabanales, Ed. Marie Curie, E-14071 Córdoba, Spain
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García-Raya D, Madueño R, Sevilla JM, Blázquez M, Pineda T. Electrochemical characterization of a 1,8-octanedithiol self-assembled monolayer (ODT-SAM) on a Au(111) single crystal electrode. Electrochim Acta 2008. [DOI: 10.1016/j.electacta.2008.06.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Madueño R, García-Raya D, Viudez AJ, Sevilla JM, Pineda T, Blázquez M. Influence of the solution pH in the 6-mercaptopurine self-assembled monolayer (6MP-SAM) on a Au(111) single-crystal electrode. Langmuir 2007; 23:11027-33. [PMID: 17902711 DOI: 10.1021/la701231d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Self-assembled monolayers (SAMs) of 6-mercaptopurine (6MP) have been prepared on a Au(111) single-crystal electrode by immersion of the metal surface in a 100 microM 6MP and 0.01 M HClO4 solution. The 6MP-SAM Au(111) single-crystal electrodes were transferred to the cell and allowed to equilibrate with the different aqueous working solutions before the electrochemical experiments. The influence of the solution pH was studied by cyclic voltammetry, double layer capacitance curves, and electrochemical impedance spectroscopy. The electrochemical behavior of the 6MP-SAM in acetic acid at pH 4 presents important differences in comparison to that obtained in 0.1 M KOH solutions. Cyclic voltammograms for the reductive desorption process in acid medium are broad and show some features that can be explained by a phase transition between a chemisorbed and a physisorbed state of the 6MP molecules. The low solubility of these molecules in acid medium could explain this phenomenon and the readsorption of the complete monolayer when the potential is scanned in the positive direction. The variation of the double-layer capacitance values in the potential range of monolayer stability with the pH suggests that the acid-base chemistry of the 6MP molecules is playing a role. This fact has been studied by following the variations of the electron-transfer rate constant of the highly charged redox probes as are Fe(CN)(6)-3/-4 and Ru(NH3)(6)+3/+2 as a function of solution pH. The apparent surface pKa value for the 6MP-SAM (pKa approximately 8) is explained by the total conversion of the different 6MP tautomers that exist in solution to the thiol species in the adsorbed state.
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Affiliation(s)
- Rafael Madueño
- Departamento de Química Física y Termodinámica Aplicada, Universidad de Córdoba, Campus de Rabanales, Ed. Marie Curie, E-14071 Córdoba, Spain
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Viudez AJ, Madueño R, Pineda T, Blázquez M. Stabilization of Gold Nanoparticles by 6-Mercaptopurine Monolayers. Effects of the Solvent Properties. J Phys Chem B 2006; 110:17840-7. [PMID: 16956270 DOI: 10.1021/jp062165l] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
6-Mercaptopurine-coated gold nanoparticles (6MP-AuNPs) have been prepared by modification of the nanoparticle surface with 6MP upon displacement of the protective layer of citrate anions. The modification has been studied by UV-vis and FTIR spectroscopies. A study of the stability of these 6MP-AuNPs in aqueous solutions as a function of ionic strength and pH has shown the importance of the charges on the stabilization. The protonation of N9 of the 6MP molecules brings about a sudden flocculation phenomenon. However, the flocculation is reversible upon changing the pH to values where the molecules become newly charged. Evidence of the competence between the interaction of capping solvent molecules and the attractive forces between particles is also shown in this paper.
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Affiliation(s)
- Alfonso J Viudez
- Departamento de Química Física y Termodinamica Aplicada, Universidad de Córdoba, Campus de Rabanales, Ed. Marie Curie, E-14071 Córdoba, Spain
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21
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Madueño R, Pineda T, Sevilla J, Blázquez M. The kinetics of the dissolution of 6-mercaptopurine self-assembled monolayers on Au(111) and Hg electrodes. J Electroanal Chem (Lausanne) 2005. [DOI: 10.1016/j.jelechem.2004.10.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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22
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Madueño R, Pineda T, Sevilla JM, Blázquez M. Formation and Dissolution Processes of the 6-Thioguanine (6TG) Self-Assembled Monolayer. A Kinetic Study. J Phys Chem B 2005; 109:1491-8. [PMID: 16851120 DOI: 10.1021/jp046642g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This is a report on the kinetics of the destruction and formation processes of the 6-thioguanine self-assembled monolayer (6TG SAM) on a mercury electrode from acid solutions by chronoamperometry. The destruction of the 6TG SAM that has been previously formed under open circuit potential conditions is carried out by stepping the potential from an initial value where the chemisorbed layer is stable up to potentials where the molecules are no longer chemisorbed. The destruction of the SAM has been described by a model that involves three types of contributions: (i) a Langmuir-type adsorption process, (ii) a 2D nucleation mechanism followed by a growth controlled by surface diffusion, and (iii) a 2D nucleation mechanism followed by a growth at a constant rate. The nonlinear fit of the experimental transients by using this procedure allows the quantitative determination of the individual contributions to the overall process. The kinetics of the formation process is studied under electrochemical conditions. The chronoamperometric experiment allows us to monitor the early stages of 6TG SAM formation. The implications of the physisorbed state at low potentials in the type of monolayer formation and destruction processes as well as the influence of temperature are also discussed.
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Affiliation(s)
- Rafael Madueño
- Departamento de Química Física y Termodinamica Aplicada, Universidad de Córdoba, Campus de Rabanales, Ed. Marie Curie, E-14071 Córdoba, Spain
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23
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Blázquez M, Pineda T, Sevilla JM, Domínguez M, García-Blanco F. The schiff base between pyridoxal-5′-phosphate (PLP) and hexylamine. Formation of the unprotonated form of the imine by reaction of the unprotonated PLP and free amine. J PHYS ORG CHEM 2004. [DOI: 10.1002/poc.610040609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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24
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Blázquez M, Blázquez B, García A. [Simultaneous finding of right trigeminal nerve schwannomas and left frontal arteriovenous malformation]. Neurologia 2003; 18:158-9. [PMID: 12677482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Affiliation(s)
- M Blázquez
- Servicio de Neurología, Hospital Central de Asturias, Oviedo, Spain.
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25
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Blázquez M, Koornneef M, Putterill J. Flowering on time: genes that regulate the floral transition. Workshop on the molecular basis of flowering time control. EMBO Rep 2001; 2:1078-82. [PMID: 11743019 PMCID: PMC1084172 DOI: 10.1093/embo-reports/kve254] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- M Blázquez
- Instituto de Biología Molecular y Celular de Plantas (CSIC-UPV), Universidad Politecnica de Valencia, 46022 Valencia, Spain
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Roman A, Sevilla J, Pineda T, Blázquez M. A study on maxima and inverted peaks in cyclic voltammetry. Electrochemical reduction of pyridine-4-aldoxime at an HMDE. J Electroanal Chem (Lausanne) 2001. [DOI: 10.1016/s0022-0728(01)00653-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Abstract
Prohormone convertase 3 (PC3) is a neuroendocrine-specific member of the subtilisin-kexin family, involved in the intracellular processing and maturation of prohormones and proneuropeptides. PC3 is synthesised as a proprotein that undergoes two different cleavages resulting in the mature PC3 and the enzymatically active PC3DeltaC. In vitro translated proPC3 and proPC3DeltaC bind to trans-Golgi network (TGN)/granule-enriched membranes from the AtT20 neuroendocrine cell line in a pH-dependent manner suggesting both a dominant role for the pro-region in membrane association and that the C-terminal region is not essential. However, while PC3 bound to membranes the majority of PC3DeltaC did not, suggesting that either the pro-region or the C-terminal region of PC3 is required for membrane association. Removal of peripheral membrane proteins did not affect the binding properties of any of the in vitro translated proteins. Chromaffin granule membranes (CGMs) were used to study the binding characteristics of endogenous PC3 and its active C-terminal truncated counterpart (PC3DeltaC). Incubation of CGMs with Triton X-100 did not completely solubilise either of these forms of PC3. Moreover, both PC3 and PC3DeltaC remained associated with detergent-resistant membrane microdomains, termed lipid rafts, purified from CGMs. The data raise the possibility that PC3 and PC3DeltaC are sorted to the regulated secretory pathway via their association with membrane lipid rafts.
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Affiliation(s)
- M Blázquez
- Department of Molecular and Cell Biology, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
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28
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Madueño R, Sevilla J, Pineda T, Román A, Blázquez M. A voltammetric study of 6-mercaptopurine monolayers on polycrystalline gold electrodes. J Electroanal Chem (Lausanne) 2001. [DOI: 10.1016/s0022-0728(01)00482-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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29
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Blázquez M, Shennan KI. Basic mechanisms of secretion: sorting into the regulated secretory pathway. Biochem Cell Biol 2001; 78:181-91. [PMID: 10949073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Targeting proteins to their correct cellular location is crucial for their biological function. In neuroendocrine cells, proteins can be secreted by either the constitutive or the regulated secretory pathways but the mechanism(s) whereby proteins are sorted into either pathway is unclear. In this review we discuss the possibility that sorting is either an active process occurring at the level of the trans-Golgi network, or that sorting occurs passively in the immature granules, The possible involvement of protein-lipid interactions in the sorting process is also raised.
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Affiliation(s)
- M Blázquez
- Department of Molecular and Cell Biology, University of Aberdeen, Institute of Medical Sciences, Foresterhill
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30
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Bosma PT, Blázquez M, Fraser EJ, Schulz RW, Docherty K, Trudeau VL. Sex steroid regulation of glutamate decarboxylase mRNA expression in goldfish brain is sexually dimorphic. J Neurochem 2001; 76:945-56. [PMID: 11181814 DOI: 10.1046/j.1471-4159.2001.00086.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Testosterone and oestradiol can modulate GABA synthesis in sexually regressed goldfish. Here we investigated their effects on the mRNA expression of two isoforms of the GABA synthesizing enzyme glutamate decarboxylase (GAD(65) and GAD(67), EC 4.1.1.15). Full-length GAD clones were isolated from a goldfish cDNA library and sequenced. Goldfish GAD(65) encodes a polypeptide of 583 amino acid residues, which is 77% identical to human GAD(65). Goldfish GAD(67) encodes a polypeptide of 587 amino acid residues and is 82% identical to human GAD(67). Goldfish GAD(65) and GAD(67) are 63% identical. Sexually regressed male and female goldfish were implanted with solid silastic pellets containing testosterone, oestradiol or no steroid. Semiquantitative PCR analysis showed that oestradiol significantly increased GAD(65) mRNA expression in female hypothalamus and telencephalon, while testosterone resulted in a significant increase only in telencephalon. GAD(67) mRNA levels were not affected by steroids in females. In contrast, both steroids induced significant decreases of GAD(65) and GAD(67) mRNA levels in male hypothalamus, but had no effect on GAD mRNA expression in male telencephalon. Our results indicate that modulation of GAD mRNA expression is a possible mechanism for steroid action on GABA synthesis, which may have opposite effects in males and females.
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Affiliation(s)
- P T Bosma
- Department of Molecular and Cell Biology, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
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31
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Affiliation(s)
- S Abel
- University of California Davis, California, USA
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32
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Pineda T, Sevilla J, Román A, Blázquez M. Electrooxidation of pyridoxal (PL) on a polycrystalline gold electrode in alkaline solutions. J Electroanal Chem (Lausanne) 2000. [DOI: 10.1016/s0022-0728(00)00258-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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33
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Blázquez M, Thiele C, Huttner WB, Docherty K, Shennan KI. Involvement of the membrane lipid bilayer in sorting prohormone convertase 2 into the regulated secretory pathway. Biochem J 2000; 349 Pt 3:843-52. [PMID: 10903147 PMCID: PMC1221213 DOI: 10.1042/bj3490843] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Prohormone convertase 2 (PC2) is a neuroendocrine-specific protease involved in the intracellular maturation of prohormones and proneuropeptides. PC2 is synthesised as a proprotein (proPC2) that undergoes proteolysis, aggregation and membrane association during its transit through the regulated secretory pathway. We have previously shown that the pro region of proPC2 plays a key role in its aggregation and membrane association. To investigate this further, we determined the binding properties of a peptide containing amino acids 45-84 of proPC2 (proPC2(45-84)) to trans-Golgi network/granule-enriched membranes from the AtT20 cell line. Removal of peripheral membrane proteins or hydrolysis of integral membrane proteins did not affect the binding properties of proPC2(45-84). Rather, proPC2(45-84) was shown to bind to protein-free liposomes in a pH- and Ca(2+)-dependent manner. To identify the component of the lipid bilayer involved in this membrane association, we used chromaffin-granule membranes and studied the binding properties of the endogenous PC2. Treatment of the membranes with saponin, a cholesterol-depleting detergent, failed to extract PC2 from the membranes, whereas chromogranin A (CgA) was removed. Treatment of the membranes with Triton X-100 yielded a low-density detergent-insoluble fraction enriched in PC2, but not CgA. The detergent-insoluble fraction also contained glycoprotein III, known to be part of the lipid rafts (membrane microdomains rich in sphingolipids). Finally, sphingolipid depletion of AtT20 cells resulted in the mis-sorting of PC2, suggestive of a link between the association of PC2 with lipid rafts in the membrane and its sorting into the regulated secretory pathway.
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Affiliation(s)
- M Blázquez
- Department of Molecular and Cell Biology, Institute of Medical Sciences. University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, U.K
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34
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Affiliation(s)
- M Blázquez
- Instituto de Biologia Molecular y Celular de Plantas (CSIC), Universidad Politecnica de Valencia, Camino de Vera s/n, Spain
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35
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Bosma PT, Blázquez M, Collins MA, Bishop JD, Drouin G, Priede IG, Docherty K, Trudeau VL. Multiplicity of glutamic acid decarboxylases (GAD) in vertebrates: molecular phylogeny and evidence for a new GAD paralog. Mol Biol Evol 1999; 16:397-404. [PMID: 10331265 DOI: 10.1093/oxfordjournals.molbev.a026120] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The evolution of chordate glutamic acid decarboxylase (GAD; EC 4.1.1.15), a key enzyme in the central nervous system synthesizing the neurotransmitter gamma-amino-butyric acid (GABA) from glutamate, was studied. Prior to this study, molecular data of GAD had been restricted to mammals, which express two distinct forms, GAD65 and GAD67. These are the products of separate genes and probably are derived from a common ancestral GAD following gene duplication at some point during vertebrate evolution. To enable a comprehensive phylogenetic analysis, molecular information of GAD forms in other vertebrate classes was essential. By reverse transcriptase-polymerase chain reaction (RT-PCR), partial nucleotide sequences of GAD were cloned from brains of zebra finch (Taeniopygia guttata), turtle (Trachemys scripta), goldfish (Carassius auratus), zebrafish (Danio rerio), and armoured grenadier (Coryphaenoides (Nematonurus) armatus, a deep-sea fish), and from the cerebral ganglion plus neural gland of Ciona intestinalis, a protochordate. Whereas GAD65 and GAD67 homologs were expressed in birds, reptiles, and fish, only a single GAD cDNA with equal similarities to both vertebrate GAD forms was found in the protochordate. This indicates that the duplication of the vertebrate GAD gene occurred between 400 and 560 million years ago. For both GAD65 and GAD67, the generated phylogenetic tree followed the general tree topology for the major vertebrate classes. In turtle, an alternative spliced form of GAD65, putatively encoding a truncated, nonactive GAD, was found. Furthermore, a third GAD form, which is equally divergent from both GAD65 and GAD67, is expressed in C. (N.) armatus. This third form might have originated from an ancient genome duplication specific to modern ray-finned fishes.
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Affiliation(s)
- P T Bosma
- Department of Zoology, University of Aberdeen, U.K
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36
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Adeva MT, Blázquez M, Ciudad J. [Cervical myelopathy due to a tumor of the foramen magnum]. Rev Neurol 1999; 28:435. [PMID: 10714331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Affiliation(s)
- M T Adeva
- Servicio de Neurología, Hospital Universitario de Salamanca, España
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37
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del Mar Marcos M, Adeva T, Blázquez M. [Man-in-the-barrel syndrome]. Rev Neurol 1999; 28:212. [PMID: 10101787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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38
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Blázquez M, Bosma PT, Chang JP, Docherty K, Trudeau VL. Gamma-aminobutyric acid up-regulates the expression of a novel secretogranin-II messenger ribonucleic acid in the goldfish pituitary. Endocrinology 1998; 139:4870-80. [PMID: 9832423 DOI: 10.1210/endo.139.12.6339] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
An RNA-arbitrarily primed PCR differential display strategy was used to identify candidate genes in the pituitary that are up-regulated by endogenously activated gamma-aminobutyric acid (GABA) systems that may also be involved in the control of reproduction. Goldfish were injected with the GABA metabolism inhibitor gamma-vinyl-GABA (GVG), known for its high efficiency to specifically increase endogenous brain and pituitary GABA levels in this species, resulting in higher levels of circulating gonadotropin-II (GTH-II). Several transcripts related to hormone secretion, signal transduction pathways, and messenger RNA (mRNA) editing were shown to be up-regulated after GVG injection. Among these transcripts we characterized an mRNA coding for the secretory vesicle protein secretogranin-II (SgII), a member of the chromogranin family, which is the precursor of a novel 34 amino acid neuropeptide, goldfish secretoneurin (SN). A semiquantitative PCR developed to measure pituitary SgII mRNA levels showed a 5-fold increase in GVG treated fish vs. control fish. Moreover, GVG treatment specifically increased SgII mRNA levels in gonadotrophs, concomitant with a decrease in GTH-II cell content. In addition, i.p. injection of synthetic goldfish SN increased GTH-II release in goldfish pretreated with the dopamine antagonist domperidone. Activation of GABAergic neurons has two effects, enhancing in vivo GTH-II release and up-regulating SgII mRNA specifically in goldfish gonadotrophs. Together with our SN bioactivity data, this suggests the existence in the pituitary of an autocrine or paracrine mechanism linked to the regulated secretory pathway in the gonadotrophs.
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Affiliation(s)
- M Blázquez
- Department of Zoology, University of Aberdeen, United Kingdom
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Sevilla J, Pineda T, Román A, Madueño R, Blázquez M. The direct electrochemistry of cytochrome c at a hanging mercury drop electrode modified with 6-mercaptopurine. J Electroanal Chem (Lausanne) 1998. [DOI: 10.1016/s0022-0728(98)00075-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Blázquez M, Bosma PT, Fraser EJ, Van Look KJ, Trudeau VL. Fish as models for the neuroendocrine regulation of reproduction and growth. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 1998; 119:345-64. [PMID: 9827007 DOI: 10.1016/s0742-8413(98)00023-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Models are essential for the full understanding of neuroendocrine control processes. In this regard fish offer a rich source of biological material. They have diverse growth and reproductive strategies, inhabiting most of the Earth's aquatic ecological niches. Fish possess many of the common vertebrate features but also offer several unique aspects to allow the biologist easy access to the study of hypothalamic and pituitary function. Several key examples of how teleosts, or the bony fish, can offer insight into fundamental mechanisms of vertebrate sex differentiation, growth and reproduction are reviewed.
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Affiliation(s)
- M Blázquez
- Department of Zoology, University of Aberdeen, UK
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Abstract
To explore a new approach for characterizing the molten globule conformation, cyclic voltammetric studies of salt induced transitions at acidic pH of cyt c have been carried out. The use of modified electrodes has made the observation of direct electrochemistry in native cyt c possible. However, most of these electrodes do not show reversible responses at acidic pH, due to the fact that, for this system, a deprotonated electrode surface is needed. In these studies, we have used a 6-mercaptopurine and cysteine-modified gold electrodes which are effective for direct rapid electron transfer to cyt c, even in acid solutions. The change in the absorption bands of cyt c are used to monitor the conformational states and, hence, to compare the voltammetric results. Under the experimental conditions where the A state of cyt c is obtained, a reversible voltammetric signal is observed. The midpoint peak potentials are found to be very close to the formal potential of native cyt c. Results are discussed in terms of a cooperative two-state transition between the acid unfolded and the globular acidic states of cyt c. This finding establishes, for the first time, the similarity of both the native and the molten globule-like conformations in terms of its redox properties.
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Affiliation(s)
- T Pineda
- Departamento de Química Física y Termodinámica Aplicada, Facultad de Ciencias, Universidad de Córdoba, Spain
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Blázquez M, Fominaya JM, Hofsteenge J. Oxidation of sulfhydryl groups of ribonuclease inhibitor in epithelial cells is sufficient for its intracellular degradation. J Biol Chem 1996; 271:18638-42. [PMID: 8702516 DOI: 10.1074/jbc.271.31.18638] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Ribonuclease inhibitor (RI) is a cytoplasmic protein (50 kDa) that inhibits a variety of pancreatic type RNases. The porcine inhibitor contains 30 cysteine residues, all of which occur in the reduced state. It is well known that in vitro modification of the thiol groups inactivates the protein and greatly increases its susceptibility to proteolysis. Here we show that oxidation of thiol groups in RI can also occur within the cell. Induction of an oxidative insult in cultured LLC-PK1 cells, either with a general oxidant, H2O2, or with a thiol-specific oxidant, diamide, led to the loss of RI activity. By using specific antibodies it was demonstrated that the decrease correlated with a decline in the amount of RI protein in the cells. Furthermore, analysis of RI mRNA levels and half-life of the protein excluded inhibition of the synthesis of RI as the cause of its depletion. The results indicate that oxidation of thiol groups in RI is sufficient to cause its rapid inactivation and disappearance from the cell. Most likely this results from intracellular degradation of the protein.
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Affiliation(s)
- M Blázquez
- Friedrich Miescher-Institut, CH-4002 Basel, Switzerland
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Sevilla JM, Cambron G, Pineda T, Blázquez M. Electroreduction of the Schiff base of pyridoxal-5′-phosphate and hexylamine in dimethylformamide and methanol. Effect of the self-protonation. J Electroanal Chem (Lausanne) 1995. [DOI: 10.1016/0022-0728(94)03695-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Casal M, Blázquez M, Gamo J, Gancedo C, Leão C. Transport of lactate and its regulation in Saccharomyces cerevisiae mutants deficient in specific metabolic steps. Folia Microbiol (Praha) 1994; 39:512. [PMID: 8550003 DOI: 10.1007/bf02814076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- M Casal
- Departamento de Biologia, Universidade do Minho, Portugal
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Squella J, Mosre J, Blázquez M, Nú≈nez-Vergara LJ. Cyclic voltammetric study of the nitro radical anion from nitrendipine generated electrochemically. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/0022-0728(91)87076-g] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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del Vado MG, Echevarria GR, Blanco FG, Santos Blanco JG, Blázquez M, Sevilla JM, Dominguez M. Schiff bases of pyridoxal 5′-phosphate and polypeptides containing L-lysine: A kinetic study. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/0304-5102(91)80095-k] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Rodríguez Mellado J, Blázquez M, Domínguez M. Derivation and experimental verification of approximate explicit equations in differential pulse polarography. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/0022-0728(88)85132-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Rodríguez-Mellado J, Blázquez M, Ruiz J. Some aspects on the role of proton donors in the electrochemical reduction of dicarbonyl compounds. Electrochim Acta 1986. [DOI: 10.1016/0013-4686(86)87061-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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