Francisco Solano

Francisco Solano
University of Murcia | UM · Department of Biochemistry and Molecular Biology B and Immunology

Prof.

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180
Publications
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7,343
Citations
Additional affiliations
January 2009 - present
Museo Nacional de Ciencias Naturales
January 1996 - present
Université Libre de Bruxelles
January 1995 - December 1999
National Institutes of Health

Publications

Publications (180)
Article
Full-text available
Central metabolic pathways may play a major role in the virulence of pathogenic fungi. Here, we have investigated the susceptibility of a Candida parapsilosis mutant deficient in trehalase activity (atc1Δ/ntc1Δ strain) to the azolic compounds fluconazole and itraconazole. A time-course exposure to itraconazole but not fluconazole induced a signific...
Preprint
Central metabolic pathways may play a major role in the virulence of pathogenic fungi. Here, we have investigated the susceptibility of a Candida parapsilosis mutant deficient in trehalase activity (atc1Δ/ntc1Δ strain) to the azolic compounds Fluconazole and Itraconazole. A time-course exposure to Itraconazole but not Fluconazole induced a signific...
Article
Full-text available
Current antifungal chemotherapy against the prevalent basidiomycete Cryptococcus neoformans displays some drawbacks. This pathogenic fungus is refractory to echinocandins, whereas conventional treatment with amphotericin B plus 5-fluorocytosine has a limited efficacy. In this study, we explored the potential cryptococcal activity of some natural ag...
Chapter
Amino acids are the building blocks of all proteins, including the most abundant fibrous proteins in the skin, as keratins, collagen and elastin. Sagging and wrinkled skin are features of chronic sun-damaged and aged uncared skin, and they are mainly associated with the deterioration of collagen and elastic fibers. The maintenance of skin structure...
Article
Full-text available
The potential fungicidal action of the natural extracts, carnosic acid (obtained from rosemary) and propolis (from honeybees’ panels) against the highly prevalent yeast Candida albicans, used herein as an archetype of pathogenic fungi, was tested. The separate addition of carnosic acid and propolis on exponential cultures of the standard SC5314 C....
Article
Full-text available
Direct sun exposure is one of the most aggressive factors for human skin. Sun radiation contains a range of the electromagnetic spectrum including UV light. In addition to the stratospheric ozone layer filtering the most harmful UVC, human skin contains a photoprotective pigment called melanin to protect from UVB, UVA, and blue visible light. This...
Article
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Industrial synthetic dyes cause health and environmental problems. This work describes the isolation of 84 bacterial strains from the midgut of the Lasius niger ant and the evaluation of their potential application in dye bioremediation. Strains were identified and classified as judged by rRNA 16S. The most abundant isolates were found to belong to...
Article
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Hormones have not been found in concentrations of orders of magnitude higher than nanograms per milliliter. Here we report urine concentrations of a catecholamine (norepinephrine) ranging from 0.05 to 0.5 g/l, and concentrations of its metabolite DL-3,4-dihydroxyphenyl glycol (DOPEG) ranging from 1.0 to 44.5 g/l, in wild male red deer Cervus elaphu...
Article
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We evaluated the kinetic characteristics of wild type (WT) and three engineered variants (RVC10, RV145, and C10_N322S) of tyrosinase from Ralstonia solanacearum and their potential as biocatalysts to produce halogenated catechols. RV145 exhibited a 3.6- to 14.5-fold improvement in catalytic efficiency (kcat/Km) with both reductions in Km and increa...
Article
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The objective of this study was to determine whether the use of the most commonly prescribed antibiotics and non-steroidal anti-inflammatory drugs in childhood could disturb enamel mineralization. Forty-two Swiss mice were divided into seven groups: controls; amoxicillin; amoxicillin/clavulanate; erythromycin; acetaminophen; ibuprofen and celecoxib...
Article
Full-text available
The production of pigment in mammalian melanocytes requires the contribution of at least three melanogenic enzymes, tyrosinase and two other accessory enzymes called the tyrosinase-related proteins (Trp1 and Trp2), which regulate the type and amount of melanin. The last two proteins are paralogues to tyrosinase, and they appeared late in evolution...
Article
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Background: Hepatic cirrhosis is associated with a variety of hemodynamic and hydrodynamic abnormalities, including renal dysfunction with salt and water retention leading to ascites and dilutional hyponatremia. Objective: In the present study, a proteomic analysis of the kidney of rats subjected to bile duct ligation (BDL) has been carried out in...
Article
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The huge development of bioengineering during the last years has boosted the search for new bioinspired materials, with tunable chemical, mechanical, and optoelectronic properties for the design of semiconductors, batteries, biosensors, imaging and therapy probes, adhesive hydrogels, tissue restoration, photoprotectors, etc. These new materials sho...
Chapter
Melanins are polyphenolic pigments widely distributed in living organisms. There are a few types of melanins, although all of them show ill-defined chemical structure. Basically, most of melanins present common features related to their protective functions. Melanins absorb electromagnetic radiations, including the UV and visible range, but they ar...
Article
Full-text available
Melanins are the ubiquitous pigments distributed in nature. They are one of the main responsible of colors in living cells. Birds are among the most diverse animals regarding melanin-based coloration, especially in the plumage, although they also pigment bare parts of the integument. This review is devoted to the main characteristics of bird melani...
Article
Melanin is the main pigment in animal skin. It is a heterogeneous polyphenolic molecule with a generalized absorption in the UV-visible range synthesized in melanocytes, a kind of specialized epidermal cells. There are two types of melanin, eumelanin and pheomelanin, more abundant in dark or fair skin respectively. Melanin plays several roles, but...
Chapter
Ma.ri.no.mo' nas. L. adj. marinus pertaining to the sea; Gr. n. monas a unit, monad; M.L. Marinomonas sea monad. Proteobacteria / Gammaproteobacteria / Oceanospirillales / Oceanospirillaceae / Marinomonas Gram-negative, straight or curved rods. Motile by means of polar flagella at one or both poles. Aerobic, having a strictly respiratory type of me...
Article
Knowledge of melanin chemistry has important implications for the study of the evolutionary ecology of animal pigmentation, but the actual chemical diversity of these widely expressed biological pigments has been largely overlooked. Considering all melanin forms and the different conditions of endogenous oxidative stress during their synthesis prov...
Cover Page
Full-text available
This male black-eared wheatear (Oenanthe hispanica) was photographed at Perabad Mountains in Ciudad Real, Spain, by Rafael Palomo Santana. The bird’s plumage coloration is generated by different chemical forms of melanins.
Article
Buthionine sulfoximine (BSO) is a specific inhibitor of γ-glutamylcysteine synthetase, thus blocking the synthesis of glutathione (GSH). It is known that this makes that BSO affects melanin synthesis because of the role of thiols in melanogenesis. However, BSO may also react with the intermediate oxidation products of melanogenesis, a possibility t...
Article
Full-text available
This review presents a general view of all types of melanin in all types of organisms. Melanin is frequently considered just an animal cutaneous pigment and is treated separately from similar fungal or bacterial pigments. Similarities concerning the phenol precursors and common patterns in the formation routes are discussed. All melanins are formed...
Article
The quantification of melanins is a complex task due to the chemical heterogeneity of the pigments and the difficulty of their isolation. The best accepted procedure currently consists in the chemical cleavage of melanins and the subsequent detection of degradation products by HPLC, which implies the destruction of samples. Here we show that Raman...
Article
Marinomonas mediterranea is a marine gamma-proteobacterium that synthesizes LodA, a novel L-lysine-ε-oxidase (E.C. 1.4.3.20). This enzyme oxidizes L-lysine generating 2-aminoadipate 6-semialdehyde, ammonium, and hydrogen peroxide. Unlike other L-amino acid oxidases, LodA is not a flavoprotein but contains a quinone cofactor. LodA is encoded by an o...
Article
The tyrosinase gene from Ralstonia solanacearum (GenBank NP518458) was subjected to random mutagenesis resulting in tyrosinase variants (RVC10 and RV145) with up to 3.2 fold improvement in k(cat) , 5.2 fold lower Km and 16 fold improvement in catalytic efficiency for D-tyrosine. Based on RVC10 and RV145 mutated sequences, single mutation variants w...
Article
Full-text available
Mature cactus pears from Opuntia stricta have a dark purple color due to high betacyanin concentration, whose biosynthesis is initiated with the amino acid L-tyrosine as a primary precursor. This study followed the maturation and ripening processes of Opuntia stricta fruits to harvest them at high betacyanin and other antioxidant concentrations. Fr...
Article
o-Quinones are easily formed by oxidation of physiologically relevant catechols. These reactions mainly occur in two specialized cells, catecholaminergic neurons and melanocytes. Both types of cells are related ontogenetically, as they arise from the neural crest during the developmental differentiation. o-Quinones are used to form melanin, a prote...
Article
Full-text available
The identification and study of marine microorganisms with unique physiological traits can be a very powerful tool discovering novel enzymes of possible biotechnological interest. This approach can complement the enormous amount of data concerning gene diversity in marine environments offered by metagenomic analysis, and can help to place the activ...
Article
The melanogenic marine bacterium Marinomonas mediterranea synthesizes a novel antimicrobial protein (LodA) with lysine-epsilon oxidase activity (EC 1.4.3.20). Homologues to LodA have been detected in several Gram-negative bacteria, where they are involved in biofilm development. Adjacent to lodA is located a second gene, lodB, of unknown function....
Article
Full-text available
Tyrosinases are widely distributed in nature. They are copper-containing oxidases belonging to the type 3 copper protein family, together with catechol oxidases and haemocyanins. Tyrosinases are essential enzymes in melanin biosynthesis and therefore responsible for pigmentation of skin and hair in mammals, where two more enzymes, the tyrosinase-re...
Article
Mammalian tyrosinase exists in a variety of subcellular locations and maturation states that result from a complex post-translational processing with possible regulatory implications. So far, SDS-PAGE has proven to be the method of choice for the resolution of tyrosinase isoforms. However, the relatively poor sensitivity of the currently available...
Article
Full-text available
Two purple pigmented bacterial strains, CPMOR-1 and CPMOR-2, have been newly isolated from the Mediterranean Sea. 16S RNA sequencing and phenotypic characteristics indicate that they belong to the species Pseudoalteromonas luteoviolacea. The synthesis of macromolecules with antimicrobial activity is a capacity described in many strains of this spec...
Article
Tyrosinases are the first and rate-limiting enzymes in the synthesis of melanin pigments responsible for colouring hair, skin and eyes. Mutation of tyrosinases often decreases melanin production resulting in albinism, but the effects are not always understood at the molecular level. Homology modelling of mouse tyrosinase based on recently published...
Article
Full-text available
Tyrosinase activity and melanin synthesis in the marine bacterium Marinomonas mediterranea in media with very low copper concentrations are dependent on the presence of a protein (PpoB2) that functions as a chaperone to deliver copper to tyrosinase (PpoB1). Under these conditions, mutants in ppoB2 (such as strain T105) produce PpoB1 as an apoenzyme...
Article
An overview of agents causing hypopigmentation in human skin is presented. The review is organized to put forward groups of biological and chemical agents. Their mechanisms of action cover (i) tyrosinase inhibition, maturation and enhancement of its degradation; (ii) Mitf inhibition; (iii) downregulation of MC1R activity; (iv) interference with mel...
Article
The melanogenic marine bacterium M. mediterranea synthesizes marinocine, a protein with antibacterial activity. We cloned the gene coding for this protein and named it lodA [P. Lucas-Elío, P. Hernández, A. Sanchez-Amat, F. Solano, Purification and partial characterization of marinocine, a new broad-spectrum antibacterial protein produced by Marinom...
Article
Full-text available
Marinocine is a broad-spectrum antibacterial protein synthesized by the melanogenic marine bacterium Marinomonas mediterranea. This work describes the basis for the antibacterial activity of marinocine and the identification of the gene coding for this protein. The antibacterial activity is inhibited under anaerobic conditions and by the presence o...
Article
The sequencing of the genome of Ralstonia solanacearum[Salanoubat M, Genin S, Artiguenave F, et al. (2002) Nature415, 497–502] revealed several genes that putatively code for polyphenol oxidases (PPOs). This soil-borne pathogenic bacterium withers a wide range of plants. We detected the expression of two PPO genes (accession numbers NP_518458 and N...
Article
Full-text available
Sequencing of the genome of Ralstonia solanacearum revealed several genes that putatively code for polyphenol oxidases (PPOs). To study the actual expression of these genes, we looked for and detected all kinds of PPO activities, including laccase, cresolase, and catechol oxidase activities, in cellular extracts of this microorganism. The condition...
Article
Full-text available
Dopachrome tautomerase (Dct) is a type I membrane protein and an important regulatory enzyme that plays a pivotal role in the biosynthesis of melanin and in the rapid metabolism of its toxic intermediates. Dct-mutant melanocytes carrying the slaty or slaty light mutations were derived from the skin of newborn congenic C57BL/6J non-agouti black mice...
Article
This work describes the purification and partial characterization of a novel antibacterial compound, here named marinocine, produced by Marinomonas mediterranea, a melanogenic marine bacterium with rich secondary metabolism. The antibacterial compound is a protein detected in the medium at death phase of growth. It has been purified to apparent hom...
Article
The genomic region of Marinomonas mediterranea containing the genes required for tyrosinase activity and melanin synthesis has been cloned by marker rescue using the transposon-generated, amelanogenic strain T105. Five ORFs, two incomplete and three complete, have been sequenced in the genomic region where the transposon was inserted. RT-PCR analys...
Article
Melanogenesis provides a unique target for the development of antitumour agents specific for malignant melanoma. Among the anti-melanoma compounds we have examined, 4-S-cysteaminylphenol (4-S-CAP), a phenolic amine, was found to have the most promising anti-melanoma effects. To further improve its efficacy as an anti-melanoma agent, we synthesized...
Article
Melanogenesis provides a unique target for the development of antitumour agents specific for malignant melanoma. Among the anti-melanoma compounds we have examined, 4-S-cysteaminylphenol (4-S-CAP), a phenolic amine, was found to have the most promising anti-melanoma effects. To further improve its efficacy as an anti-melanoma agent, we synthesized...
Article
Full-text available
The melanogenic marine bacterium Marinomonas mediterranea synthesizes R-bodies as revealed by transmission electron microscopy. These structures were previously described in some obligate symbionts of paramecia and some free-living bacteria, none of which was isolated from sea water. In other micro-organisms, the synthesis of R-bodies has been rela...
Article
Tyrosinase (Tyr), the rate-limiting melanogenic enzyme, is a copper-containing glycoprotein with a complex post-translational processing that involves N-glycosylation in several sites, including one located in the CuB metal binding site, exit from the endoplasmic reticulum to the Golgi, copper binding and sorting to the melanosome. Aberrant process...
Article
Melanin is the most widely distributed pigment on nature. In higher animals, the main roles of this pigment are associated to cutaneous photoprotection and proper function of the eye and inner ear, but in microorganisms melanin seems to be a polymer to enhance the survival and competitive abilities of species in certain environments, and for instan...
Article
Full-text available
Tyrosinase, the rate-limiting enzyme in mammalian melanogenesis, is a copper-containing transmembrane glycoprotein. Tyrosinase undergoes a complex post-translational processing before reaching the melanosomal membrane. This processing involves N-glycosylation in several sites, including one located in the CuB copper binding site, movement from the...
Article
Full-text available
This work studies the effect of different X-rays doses on thyroid peroxidase activity in three groups of rabbits: normofunctioning, propylthiouracil-treated and TRH-treated. The results show a significant decrease in peroxidase activity in all animals irradiated with a single or fractionated X-rays dose, produced without pathological ultrastructura...
Article
Full-text available
Marinomonas mediterranea is a melanogenic marine bacterium that expresses two different polyphenol oxidases. One of them is a multipotent laccase able to oxidize a wide range of substrates. The second enzyme is an SDS-activated tyrosinase. Using transposon mutagenesis, a mutant affected in the regulation of both polyphenol oxidase activities and me...
Article
The structure of tyrosinase (Tyr) is reviewed from a double point of view. On the one hand, by comparison of all Tyr found throughout nature, from prokaryotic organisms to mammals and on the other, by comparison with the tyrosinase related proteins (Tyrps) that appeared late in evolution, and are only found in higher animals. Their structures are r...
Article
The sequence of the tyrosinase gene cloned from Marinomonas mediterranea is reported. It is the second tyrosinase cloned from a Gram negative bacterium. Its size is higher than that of Gram positive tyrosinases from Streptomyces, and more similar to the eukaryotic enzymes. Its sequence shares the features of copper-binding sites found in all tyrosi...
Article
Ornithine decarboxylase (ODC) is the rate-limiting enzyme in the biosynthesis of polyamines, a family of cationic compounds required for optimal cell proliferation and differentiation. Within mammalian melanocytes, the expression of genes regulating cell growth and/or differentiation can be controlled by alpha-melanocyte-stimulating hormone (alphaM...
Article
Tyrosinase (Tyr) and tyrosinase-related proteins (Tyrps) 1 and 2 are the enzymes responsible for mammalian melanogenesis. They display high similarity but different substrate and reaction specificities. Loss-of-function mutations lead to several forms of albinism or other pigmentation disorders. They share two conserved metal binding sites (CuA and...
Article
Ornithine decarboxylase (ODC) is the rate-limiting enzyme in the biosynthesis of polyamines, a family of cationic compounds required for optimal cell proliferation and differentiation. Within mammalian melanocytes, the expression of genes regulating cell growth and/or differentiation can be controlled by a-melanocyte-stimulating hormone (alphaMSH)...
Chapter
This chapter summarizes our recent studies on the regulation of melanin synthesis, a chemical pathway which bears a striking resemblance to that proposed to be involved in neuromelanin production from Dopamine (DN).1 Two key enzymes, DOPAchrome tautomerase (DCT) and macrophage migration inhibitory factor (MIF), have analogous catalytic actions in t...
Article
2,6-Dimethoxyphenol is a versatile substrate for Pyricularia oryzae laccase, PpoA from Marinomonas mediterranea, phenoxazinone synthase from Streptomyces antibioticus and mammalian ceruloplasmin. In addition, in cellular extracts of microorganisms expressing other blue multicopper proteins with no enzymatic activity previously described, such as Es...
Article
Full-text available
H(2)O(2) and other reactive oxygen species are key regulators of many intracellular pathways. Within mammalian skin, H(2)O(2) is formed as a byproduct of melanin synthesis, and following u.v. irradiation. We therefore analyzed its effects on melanin synthesis. The activity of the rate-limiting melanogenic enzyme, tyrosinase, decreased in H(2)O(2)-t...
Article
Marinomonas mediterranea is a recently isolated melanogenic marine bacterium containing laccase and tyrosinase activities. These activities are due to the expression of two polyphenol oxidases (PPOs), a blue multicopper laccase and an SDS-activated tyrosinase. The gene encoding the first one, herein denominated M. mediterranea PpoA, has been isolat...
Article
Full-text available
Melanin synthesis in mammals is catalysed by at least three enzymic proteins, tyrosinase (monophenol dihydroxyphenylalanine:oxygen oxidoreductase, EC 1.14.18.1) and tyrosinase-related proteins (tyrps) 1 and 2, whose genes map to the albino, brown and slaty loci in mice, respectively. Tyrosinase catalyses the rate-limiting generation of L-dopaquinon...
Article
The pigment pattern expression resides in the chromatoblasts of the embryonic skin. The differentiation of these chromatoblasts is influenced by specific local factors such a melanization inhibiting factor (MIF) and a melanization-stimulating factor (MSF). We reveal the presence of these factors by means of a series of experiments on the skin of th...
Article
Full-text available
Marinomonas mediterranea is a melanogenic marine bacterium expressing a multifunctional polyphenol oxidase (PPO) able to oxidize substrates characteristic for laccases and tyrosinases, as well as produce a classical tyrosinase. A new and quick method has been developed for screening laccase activity in culture plates to detect mutants differentiall...