A5007483917- melanin and skin pigmentation
- Biochemical Analysis and Sensing Techniques
- Skin Protection and Aging
- RNA regulation and disease
- Enzyme-mediated dye degradation
- Polyamine Metabolism and Applications
- Microbial Metabolism and Applications
- Olfactory and Sensory Function Studies
- Macrophage Migration Inhibitory Factor
- Vascular Malformations Diagnosis and Treatment
- Computational Drug Discovery Methods
- Amino Acid Enzymes and Metabolism
- Phytochemicals and Antioxidant Activities
- Intracranial Aneurysms: Treatment and Complications
- Aquaculture disease management and microbiota
- Enzyme Catalysis and Immobilization
- Bee Products Chemical Analysis
- Bioactive Compounds and Antitumor Agents
- Biochemical effects in animals
- Nuclear Receptors and Signaling
- Intracerebral and Subarachnoid Hemorrhage Research
- Bacteriophages and microbial interactions
- Essential Oils and Antimicrobial Activity
- Receptor Mechanisms and Signaling
- Carbohydrate Chemistry and Synthesis
Universidad de Murcia
2015-2024
University of California, Santa Cruz
2024
Instituto Murciano de Investigación Biosanitaria
2017
Hospital Universitario Virgen Macarena
1998-2016
Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo
2012
Universidade Federal do Pará
2011
Richard Wolf (Germany)
2002
National Institutes of Health
1994-1999
Institut Jules Bordet
1996
Fujita Health University
1996
This review presents a general view of all types melanin in organisms. Melanin is frequently considered just an animal cutaneous pigment and treated separately from similar fungal or bacterial pigments. Similarities concerning the phenol precursors common patterns formation routes are discussed. All melanins formed first enzymatically-controlled phase, generally phenolase, second phase characterized by uncontrolled polymerization oxidized intermediates. In that quinones derived oxidation...
Since the characterization of 5,6-dihydroxyindole-2-carboxylic acid (DHICA) as a major melanogenic intermediate, fate this compound and mechanisms its incorporation into melanin polymer have become issues in study melanogenesis. DHICA is stable dihydroxyindole with low rate spontaneous oxidation, suggesting that enzymatic mechanism(s) might contribute to evolution. The most obvious candidates are melanosomal tyrosinases. We recently shown mouse melanosomes contain two electrophoretically...
H2O2 and other reactive oxygen species are key regulators of many intracellular pathways. Within mammalian skin, is formed as a byproduct melanin synthesis, following u.v. irradiation. We therefore analyzed its effects on synthesis. The activity the rate-limiting melanogenic enzyme, tyrosinase, decreased in H2O2-treated mouse human melanoma cells. This inhibition was concentration- time-dependent B16 model. Maximal (50-75%) occurred 8-16 hours after 20 minute exposure to 0.5 mM H2O2. cells...
The quantification of melanins is a complex task due to the chemical heterogeneity pigments and difficulty their isolation. best accepted procedure currently consists in cleavage subsequent detection degradation products by HPLC, which implies destruction samples. Here, we show that Raman spectroscopy non-invasive technique can be used quantify melanins. We made parallel analyses characteristics pheomelanin eumelanin spectra as measured confocal microscopy (4-amino-3-hydroxyphenylalanine,...
Abstract Melanin is the main pigment in animal skin. It a heterogeneous polyphenolic molecule with generalized absorption UV −visible range synthesized melanocytes, kind of specialized epidermal cells. There are two types melanin, eumelanin and pheomelanin, more abundant dark or fair skin respectively. plays several roles, but mammalian one related to photoprotection against sunlight. The energy from light implies that elements melanin structure photoexcited, subsequent transference can...
The inflammatory cytokine tumor necrosis factor‐α (TNF‐α) is present in the dermal and epidermal layers of normal skin [Kilgus, O., Payer, E., Schreiber, S., Elbe, A., Strohal, R. & Stingl, G. (1993) J. Invest. Dermatol. 100 , 674−680]. Its local concentrations are modified by several stimuli, including wound healing ultraviolet irradiation. Moreover, TNF‐α inhibits melanogenesis melanocytes [Swope, V., Abdel‐Malek, Z., Kassem, L. Norlund, (1991) 96 180−185], is, therefore, a potential...
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 2, whose genes map to the albino, brown slaty loci mice, respectively. Tyrosinase catalyses rate-limiting generation of l-dopaquinone from l-tyrosine also able oxidize l-dopa l-dopaquinone. Conversely, mouse tyrp1, but not tyrosinase, oxidation indolic intermediate...
A novel marine melanogenic bacterium, strain MMB-1, was isolated from the Mediterranean Sea. The taxonomic characterization of this indicated that it belongs to genus Alteromonas. Under in vivo conditions, L-tyrosine specific monophenolic precursor for melanin synthesis. This bacterium contained all types activities associated with polyphenol oxidases (PPOs), cresolase (EC 1.18.14.1), catecholase 1.10.3.1), and laccase 1.10.3.2). These were due presence two different PPOs. first one showed...
2,6-Dimethoxyphenol is a versatile substrate for Pyricularia oryzae laccase, PpoA from Marinomonas mediterranea, phenoxazinone synthase 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 Escherichia coli (copper resistance CueO), Pseudomonas syringae Xanthomonas campestris CopA), Bacillus subtilis (sporulation protein CotA) Saccharomyces...
Tyrosinase (Tyr) and tyrosinase-related proteins (Tyrps) 1 2 are the enzymes responsible for mammalian melanogenesis. They display high similarity but different substrate reaction specificities. Loss-of-function mutations lead to several forms of albinism or other pigmentation disorders. share two conserved metal binding sites (CuA CuB) which, in Tyr, bind copper. To define some structural determinants these differences, we mutated Tyr at selected residues on basis (i) conservation original...
The regulation of the final steps melanogenesis pathway, after L‐2‐carboxy‐2,3‐dihydroindole‐5,6‐quinone (dopachrome) formation, is studied. It shown that both tyrosinase and dopachrome tautomerase are involved in process. In vivo , it seems amount melanin formed, whereas mainly size, structure composition melanin, by regulating to incorporation 5,6‐dihydroxyindole‐2‐carboxylic acid (DHICA) into polymer. Moreover, using L‐3,4‐dihydroxyphenylalanine (dopa) related compounds, was presence...