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[PMID]:28465179
[Au] Autor:Mullaivanam Ramasamy S; Denis M; Sivakumar S; Munusamy A
[Ad] Endereço:Laboratory of Pathobiology, Department of Zoology, University of Madras, Guindy Campus, Chennai 600 025, Tamil Nadu, India. Electronic address: sivakumarmr1981@gmail.com.
[Ti] Título:Phenoloxidase activity in humoral plasma, hemocyanin and hemocyanin separated proteins of the giant freshwater prawn Macrobrachium rosenbergii.
[So] Source:Int J Biol Macromol;102:977-985, 2017 Sep.
[Is] ISSN:1879-0003
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Hemocyanin is a copper containing protein and its role in the immune function of phenoloxidase (PO) activity was investigated in the giant freshwater prawn Macrobrachium rosenbergii. Hemocyanin, sedimented by ultracentrifugation from the plasma appeared on polyacrylamide gel electrophoresis (PAGE 7%) on Coomassie Brilliant Blue and bathocuproine sulfonic acid stain as four copper containing proteins of molecular masses 50, 60, 114 and 325kDa. Accordingly, on diethylaminoethyl-cellulose anion exchange column hemocyanin separated into four proteins designated as MrHc1, MrHc2, MrHc3 and MrHc4 with electrophoretically (PAGE) determined molecular masses of 60, 114, 50 and 325kDa respectively. The reduction of proteins in sodium dodecyl sulphate (SDS)-PAGE revealed that MrHc1 and 3 were monomeric for 60and 50kDa respectively, MrHc2 dimeric of 56 and 58kDa subunits and MrHc4 appeared with three subunits of 74, 76 and 78kDa. The PO activity was determined in plasma, hemocyanin and the four separated hemocyanin proteins in vitro using L-3,4-dihydroxyphenylalanine (L-DOPA) at pH7.5, 25°C and appeared elicited by exogenous activators such as trypsin, SDS, cell wall components of bacteria and polysaccharide laminarin. This study clearly demonstrated hemocyanin as the major copper containing protein in the plasma of M. rosenbergii with potent PO activity.
[Mh] Termos MeSH primário: Hemocianinas/metabolismo
Imunidade Humoral
Monofenol Mono-Oxigenase/sangue
Monofenol Mono-Oxigenase/metabolismo
Palaemonidae/enzimologia
[Mh] Termos MeSH secundário: Animais
Palaemonidae/imunologia
Palaemonidae/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
9013-72-3 (Hemocyanins); EC 1.14.18.1 (Monophenol Monooxygenase)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180309
[Lr] Data última revisão:
180309
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170504
[St] Status:MEDLINE


  2 / 6223 MEDLINE  
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[PMID]:29254897
[Au] Autor:Yang HH; Oh KE; Jo YH; Ahn JH; Liu Q; Turk A; Jang JY; Hwang BY; Lee KY; Lee MK
[Ad] Endereço:College of Pharmacy, Chungbuk National University, Cheongju 28160, Republic of Korea.
[Ti] Título:Characterization of tyrosinase inhibitory constituents from the aerial parts of Humulus japonicus using LC-MS/MS coupled online assay.
[So] Source:Bioorg Med Chem;26(2):509-515, 2018 01 15.
[Is] ISSN:1464-3391
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:In the screening of natural products for the development as cosmetic ingredients, the EtOAc-soluble fraction of Humulus japonicus showed tyrosinase inhibitory activity. HPLC-MS/MS coupled online tyrosinase assay of EtOAc-soluble fraction of H. japonicus characterized the twenty-eight constituents including two unknown ones and their tyrosinase inhibitory activity. Fractionation of H. japonicus using various chromatographic techniques yielded thirty-eight compounds. The chemical structures of isolated compounds were identified by spectroscopic analysis. As characterized by HPLC-MS/MS analysis, we isolated twenty-four predicted compounds and further identified two unknown ones, named humulusides A (1) and B (2). Additional ten compounds were also identified by purification. Tyrosinase inhibitory activity of isolated compounds were evaluated, which was closely correlated with the results from HPLC-MS/MS coupled online tyrosinase assay. Consistent with predicted data, two major compounds, trans-N-coumaroyltyramine (14) and cis-N-coumaroyltyramine (15) showed tyrosinase inhibition with IC values of 40.6 and 36.4 µM. Taken together, H. japonicus is suggested as whitening ingredient in cosmetic products. In addition, HPLC-MS/MS coupled tyrosinase assay is powerful tool for predicting active compounds with short time and limited amounts, although identification of new compounds and verification of predicted data are also needs to be demonstrated by further experiment.
[Mh] Termos MeSH primário: Inibidores Enzimáticos/farmacologia
Humulus/química
Monofenol Mono-Oxigenase/antagonistas & inibidores
Componentes Aéreos da Planta/química
Extratos Vegetais/farmacologia
[Mh] Termos MeSH secundário: Cromatografia Líquida de Alta Pressão
Relação Dose-Resposta a Droga
Inibidores Enzimáticos/química
Inibidores Enzimáticos/isolamento & purificação
Seres Humanos
Estrutura Molecular
Monofenol Mono-Oxigenase/metabolismo
Extratos Vegetais/química
Extratos Vegetais/isolamento & purificação
Relação Estrutura-Atividade
Espectrometria de Massas em Tandem
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 0 (Plant Extracts); EC 1.14.18.1 (Monophenol Monooxygenase)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180220
[Lr] Data última revisão:
180220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171220
[St] Status:MEDLINE


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[PMID]:29311513
[Au] Autor:Lopes TIB; Coelho RG; Honda NK
[Ad] Endereço:Instituto de Química, Universidade Federal de Mato Grosso do Sul.
[Ti] Título:Inhibition of Mushroom Tyrosinase Activity by Orsellinates.
[So] Source:Chem Pharm Bull (Tokyo);66(1):61-64, 2018.
[Is] ISSN:1347-5223
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:Several applications have been proposed for tyrosinase inhibitors in the pharmaceutical, food bioprocessing, and environmental industries. However, only a few compounds are known to serve as effective tyrosinase inhibitors. This study evaluated the tyrosinase-related activity of resorcinol (1), orcinol (2) lecanoric acid (3), and derivatives of this acid (4-15). Subjected to alcoholysis, lecanoric acid (3), a depside isolated from the lichen Parmotrema tinctorum, produces orsellinic acid (2,4-dihydroxy-6-methylbenzoic acid) (4) and orsellinates (2,4-dihydroxy-6-methyl benzoates) (5-15). At 0.50 mM, methyl (5), ethyl (6), n-propyl (7), tert-butyl (11), and n-cetyl orsellinates (15) acted as tyrosinase activators, whereas n-butyl (8), iso-propyl (9), sec-butyl (10), n-pentyl (12), n-hexyl (13), and n-octyl orsellinates (14) behaved as inhibitors. Tyrosinase inhibition rose with chain elongation-n-butyl (8)
[Mh] Termos MeSH primário: Agaricales/enzimologia
Inibidores Enzimáticos/farmacologia
Líquens/química
Monofenol Mono-Oxigenase/antagonistas & inibidores
Resorcinóis/farmacologia
[Mh] Termos MeSH secundário: Relação Dose-Resposta a Droga
Inibidores Enzimáticos/química
Inibidores Enzimáticos/isolamento & purificação
Cinética
Estrutura Molecular
Monofenol Mono-Oxigenase/metabolismo
Resorcinóis/química
Resorcinóis/isolamento & purificação
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 0 (Resorcinols); 11XLA0494B (orsellinic acid); EC 1.14.18.1 (Monophenol Monooxygenase)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180213
[Lr] Data última revisão:
180213
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180110
[St] Status:MEDLINE
[do] DOI:10.1248/cpb.c17-00502


  4 / 6223 MEDLINE  
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[PMID]:29313327
[Au] Autor:Chai WM; Huang Q; Lin MZ; Ou-Yang C; Huang WY; Wang YX; Xu KL; Feng HL
[Ad] Endereço:College of Life Science and Key Laboratory of Small Functional Organic Molecule, Ministry of Education, Jiangxi Normal University , Nanchang, Jiangxi 330022, People's Republic of China.
[Ti] Título:Condensed Tannins from Longan Bark as Inhibitor of Tyrosinase: Structure, Activity, and Mechanism.
[So] Source:J Agric Food Chem;66(4):908-917, 2018 Jan 31.
[Is] ISSN:1520-5118
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In this study, the content, structure, antityrosinase activity, and mechanism of longan bark condensed tannins were evaluated. The findings obtained from mass spectrometry demonstrated that longan bark condensed tannins were mixtures of procyanidins, propelargonidins, prodelphinidins, and their acyl derivatives (galloyl and p-hydroxybenzoate). The enzyme analysis indicated that these mixtures were efficient, reversible, and mixed (competitive is dominant) inhibitor of tyrosinase. What's more, the mixtures showed good inhibitions on proliferation, intracellular enzyme activity and melanogenesis of mouse melanoma cells (B ). From molecular docking, the results showed the interactions between inhibitors and tyrosinase were driven by hydrogen bond, electrostatic, and hydrophobic interactions. In addition, high levels of total phenolic and extractable condensed tannins suggested that longan bark might be a good source of tyrosinase inhibitor. This study would offer theoretical basis for the development of longan bark condensed tannins as novel food preservatives and medicines of skin diseases.
[Mh] Termos MeSH primário: Inibidores Enzimáticos/farmacologia
Monofenol Mono-Oxigenase/antagonistas & inibidores
Casca de Planta/química
Sapindaceae/química
Taninos/química
Taninos/farmacologia
[Mh] Termos MeSH secundário: Animais
Antocianinas/farmacologia
Biflavonoides/farmacologia
Catequina/farmacologia
Proliferação Celular/efeitos dos fármacos
Ligações de Hidrogênio
Interações Hidrofóbicas e Hidrofílicas
Espectrometria de Massas
Melaninas/análise
Melaninas/antagonistas & inibidores
Melaninas/biossíntese
Melanoma Experimental
Camundongos
Modelos Moleculares
Simulação de Acoplamento Molecular
Oxirredutases
Parabenos/farmacologia
Proantocianidinas/farmacologia
Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
Eletricidade Estática
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anthocyanins); 0 (Biflavonoids); 0 (Enzyme Inhibitors); 0 (Melanins); 0 (Parabens); 0 (Proanthocyanidins); 0 (Tannins); 4852-22-6 (procyanidin); 8R1V1STN48 (Catechin); EC 1.- (Oxidoreductases); EC 1.14.18.- (monophenolase); EC 1.14.18.1 (Monophenol Monooxygenase); EM6MD4AEHE (delphinidin); JG8Z55Y12H (4-hydroxybenzoic acid)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180212
[Lr] Data última revisão:
180212
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180110
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jafc.7b05481


  5 / 6223 MEDLINE  
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[PMID]:28469016
[Au] Autor:Sterkel M; Oliveira PL
[Ad] Endereço:Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil msterkel29@gmail.com.
[Ti] Título:Developmental roles of tyrosine metabolism enzymes in the blood-sucking insect .
[So] Source:Proc Biol Sci;284(1854), 2017 May 17.
[Is] ISSN:1471-2954
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The phenylalanine/tyrosine degradation pathway is frequently described as a catabolic pathway that funnels aromatic amino acids into citric acid cycle intermediates. Previously, we demonstrated that the accumulation of tyrosine generated during the hydrolysis of blood meal proteins in is potentially toxic, a harmful outcome that is prevented by the action of the first two enzymes in the tyrosine degradation pathway. In this work, we further evaluated the relevance of all other enzymes involved in phenylalanine/tyrosine metabolism in the physiology of this insect. The knockdown of most of these enzymes produced a wide spectrum of distinct phenotypes associated with reproduction, development and nymph survival, demonstrating a highly pleiotropic role of tyrosine metabolism. The phenotypes obtained for two of these enzymes, homogentisate dioxygenase and fumarylacetoacetase, have never before been described in any arthropod. To our knowledge, this report is the first comprehensive gene-silencing analysis of an amino acid metabolism pathway in insects. Amino acid metabolism is exceptionally important in haematophagous arthropods due to their particular feeding behaviour.
[Mh] Termos MeSH primário: Monofenol Mono-Oxigenase/genética
Rhodnius/enzimologia
Tirosina/metabolismo
[Mh] Termos MeSH secundário: Animais
Inativação Gênica
Redes e Vias Metabólicas
Fenótipo
Rhodnius/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
42HK56048U (Tyrosine); EC 1.14.18.1 (Monophenol Monooxygenase)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180131
[Lr] Data última revisão:
180131
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170505
[St] Status:MEDLINE


  6 / 6223 MEDLINE  
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[PMID]:28448467
[Au] Autor:Araújo JS; Chambó ED; Costa MAPC; Cavalcante da Silva SMP; Lopes de Carvalho CA; M Estevinho L
[Ad] Endereço:Centro de Ciências Agrárias, Ambientais e Biológicas, Universidade Federal do Recôncavo da Bahia, Cruz das Almas 44380-000, Bahia, Brazil. jucilenearaujo15@hotmail.com.
[Ti] Título:Chemical Composition and Biological Activities of Mono- and Heterofloral Bee Pollen of Different Geographical Origins.
[So] Source:Int J Mol Sci;18(5), 2017 Apr 27.
[Is] ISSN:1422-0067
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:Recent research shows variations in pollen chemical constituents and, consequently, in their therapeutic properties. Mono and multifloral bee pollen extracts were investigated for antioxidant and enzyme inhibitory activity properties, phenolic compounds and fatty acid composition. Generally, spp. and multifloral extracts exhibited potent inhibitory activity against α-amylase, acetylcholinesterase, tyrosinase, lipoxygenase, lipase and hyaluronidase. On the other hand, spp. demonstrated higher antihemolytic activity. and spp. extracts exhibited important antioxidant properties in the different assays (ABTS, DPPH, ß-carotene/linoleic acid and reducing power). Moreover, these extracts had greater amounts of total phenols and flavonoids in comparison to others. The increase in antioxidant activity (decrease in EC values) was accompanied by an increase in the amount of total phenols in the extracts. The pollen extracts contained linoleic acid and α-linolenic acid as major fatty acids, followed by palmitic acid, and oleic acid. In this study, differences were observed in both chemical constituents and biological activities of the samples related to the geographical and botanical origin of bee pollen.
[Mh] Termos MeSH primário: Extratos Vegetais/química
Pólen/química
[Mh] Termos MeSH secundário: Acetilcolinesterase/química
Acetilcolinesterase/metabolismo
Animais
Antioxidantes/química
Antioxidantes/metabolismo
Abelhas
Cromatografia Gasosa
Cocos/química
Cocos/metabolismo
Eucalyptus/química
Eucalyptus/metabolismo
Ácidos Graxos/análise
Ácidos Graxos/química
Flavonoides/análise
Flavonoides/química
Melastomataceae/química
Melastomataceae/metabolismo
Monofenol Mono-Oxigenase/antagonistas & inibidores
Monofenol Mono-Oxigenase/metabolismo
Fenóis/análise
Fenóis/química
Extratos Vegetais/metabolismo
Análise de Componente Principal
alfa-Amilases/antagonistas & inibidores
alfa-Amilases/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antioxidants); 0 (Fatty Acids); 0 (Flavonoids); 0 (Phenols); 0 (Plant Extracts); EC 1.14.18.1 (Monophenol Monooxygenase); EC 3.1.1.7 (Acetylcholinesterase); EC 3.2.1.1 (alpha-Amylases)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180122
[Lr] Data última revisão:
180122
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170428
[St] Status:MEDLINE


  7 / 6223 MEDLINE  
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[PMID]:29244828
[Au] Autor:Janssen RH; Lakemond CMM; Fogliano V; Renzone G; Scaloni A; Vincken JP
[Ad] Endereço:Food Quality and Design, Wageningen University, Wageningen, The Netherlands.
[Ti] Título:Involvement of phenoloxidase in browning during grinding of Tenebrio molitor larvae.
[So] Source:PLoS One;12(12):e0189685, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Insects are investigated as alternative protein source to meet the increasing demand for proteins in the future. Enzymatic browning occurring during grinding of insect and subsequent extraction of proteins can influence the proteins' properties, but it is unclear which enzymes are responsible for this phenomenon. This study was performed on larvae of three commonly used insect species, namely Tenebrio molitor, Alphitobius diaperinus and Hermetia illucens. Oxygen consumption measurements on protein extracts showed activity on L-tyrosine, L-3,4-di-hydroxy-phenylalanine (L-DOPA) and L-dopamine, indicating phenoloxidase as a key player in browning. Furthermore, no reaction on 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) was observed, ruling out an important contribution of laccase to browning. The browning reaction was most prominent at pH 6 for T. molitor and A. diaperinus, and 7 for H. illucens. As the enzyme activity of H. illucens was the lowest with the darkest color formation, this was likely caused by another factor. The activity of phenoloxidase was confirmed for T. molitor and A. diaperinus by activity measurements after fractionation by anion-exchange chromatography. Color measurements showed the presence of activity on both L-DOPA and L-tyrosine in the same fractions. Both substrates were converted into dopachrome after incubation with enzyme-enriched fractions. No DOPA-decarboxylase, tyrosine hydroxylase and peroxidase activities were observed. By using native PAGE with L-DOPA as staining-solution, active T. molitor protein bands were resolved and characterized, identifying a tyrosinase/phenoloxidase as the active enzyme species. All together, these data confirmed that tyrosinase is an important enzyme in causing enzymatic browning in T. molitor and likely in A. diaperinus.
[Mh] Termos MeSH primário: Proteínas de Insetos/química
Reação de Maillard
Monofenol Mono-Oxigenase/química
Consumo de Oxigênio/genética
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Animais
Coleópteros/química
Coleópteros/genética
Dípteros/química
Dípteros/genética
Dopamina/química
Dopamina/genética
Proteínas de Insetos/genética
Larva/química
Larva/genética
Levodopa/química
Levodopa/genética
Monofenol Mono-Oxigenase/genética
Homologia de Sequência de Aminoácidos
Tenebrio/química
Tenebrio/genética
Tirosina/química
Tirosina/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Insect Proteins); 42HK56048U (Tyrosine); 46627O600J (Levodopa); EC 1.14.18.1 (Monophenol Monooxygenase); VTD58H1Z2X (Dopamine)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180102
[Lr] Data última revisão:
180102
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171216
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0189685


  8 / 6223 MEDLINE  
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[PMID]:28456625
[Au] Autor:Satooka H; Cerda P; Kim HJ; Wood WF; Kubo I
[Ad] Endereço:Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720-3114, United States.
[Ti] Título:Effects of matsutake mushroom scent compounds on tyrosinase and murine B16-F10 melanoma cells.
[So] Source:Biochem Biophys Res Commun;487(4):840-846, 2017 06 10.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Tyrosinase-catalyzed l-tyrosine oxidation is a key step in melanogenesis, and intense melanin formation is often a problem in chemotherapies or food preservation. Here we report that methyl cinnamate one of the constituents characterized from mycelium and sporocarp of American matsutake mushroom Tricholoma magnivelare inhibits both enzymatic and cellular melanin formation. Methyl cinnamate inhibits mushroom tyrosinase-catalyzed l-tyrosine oxidation while the oxidation of l-3,4-dihydroxyphenylalanine (l-DOPA) was not inhibited. In subsequent cellular assays, methyl cinnamate significantly suppressed melanogenesis of murine B16-F10 melanoma cells without affecting cell growth. However, methyl 3-phenylpropionate, a dihydro-derivative of methyl cinnamate, did not possess melanogenesis, indicating that the double bond in the enone moiety is a key Michael reaction acceptor to elicit the activity. In addition, a rather rare chlorinated benzaldehyde derivative, 3,5-dichloro-4-methoxybenzaldehyde isolated from the same source, was found to show potent cytotoxicity, and the chlorine atom reduced a tyrosinase inhibitory activity but enhanced cytotoxicity. Our findings suggest that methyl cinnamate is a novel melanogenesis inhibitor from natural sources.
[Mh] Termos MeSH primário: Cinamatos/farmacologia
Inibidores Enzimáticos/farmacologia
Melanoma Experimental/tratamento farmacológico
Melanoma Experimental/enzimologia
Monofenol Mono-Oxigenase/antagonistas & inibidores
Odorantes
Tricholoma/química
[Mh] Termos MeSH secundário: Animais
Sobrevivência Celular/efeitos dos fármacos
Cinamatos/química
Cinamatos/isolamento & purificação
Relação Dose-Resposta a Droga
Inibidores Enzimáticos/química
Inibidores Enzimáticos/isolamento & purificação
Melanoma Experimental/patologia
Camundongos
Monofenol Mono-Oxigenase/metabolismo
Relação Estrutura-Atividade
Tricholoma/enzimologia
Células Tumorais Cultivadas
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cinnamates); 0 (Enzyme Inhibitors); 533CV2ZCQL (methyl cinnamate); EC 1.14.18.1 (Monophenol Monooxygenase)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171128
[Lr] Data última revisão:
171128
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170501
[St] Status:MEDLINE


  9 / 6223 MEDLINE  
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[PMID]:27775880
[Au] Autor:Dolinska MB; Kus NJ; Farney SK; Wingfield PT; Brooks BP; Sergeev YV
[Ad] Endereço:National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
[Ti] Título:Oculocutaneous albinism type 1: link between mutations, tyrosinase conformational stability, and enzymatic activity.
[So] Source:Pigment Cell Melanoma Res;30(1):41-52, 2017 Jan.
[Is] ISSN:1755-148X
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Oculocutaneous albinism type 1 (OCA1) is an autosomal recessive disorder caused by mutations in the tyrosinase gene. Two subtypes of OCA1 have been described: severe OCA1A with complete absence of tyrosinase activity and less severe OCA1B with residual tyrosinase activity. Here, we characterize the recombinant human tyrosinase intramelanosomal domain and mutant variants, which mimic genetic changes in both subtypes of OCA1 patients. Proteins were prepared using site-directed mutagenesis, expressed in insect larvae, purified by chromatography, and characterized by enzymatic activities, tryptophan fluorescence, and Gibbs free energy changes. The OCA1A mutants showed very low protein expression and protein yield and are enzymatically inactive. Mutants mimicking OCA1B were biochemically similar to the wild type, but exhibited lower specific activities and protein stabilities. The results are consistent with clinical data, which indicates that OCA1A mutations inactivate tyrosinase and result in severe phenotype, while OCA1B mutations partially inactivate tyrosinase and result in OCA1B albinism.
[Mh] Termos MeSH primário: Albinismo Oculocutâneo/patologia
Monofenol Mono-Oxigenase/genética
Monofenol Mono-Oxigenase/metabolismo
Mutação/genética
Conformação Proteica
[Mh] Termos MeSH secundário: Albinismo Oculocutâneo/genética
Albinismo Oculocutâneo/metabolismo
Catálise
Seres Humanos
Modelos Moleculares
Monofenol Mono-Oxigenase/química
Dobramento de Proteína
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Recombinant Proteins); EC 1.14.18.1 (Monophenol Monooxygenase)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171128
[Lr] Data última revisão:
171128
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161025
[St] Status:MEDLINE
[do] DOI:10.1111/pcmr.12546


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[PMID]:29045474
[Au] Autor:Nakamura S; Kunikata T; Matsumoto Y; Hanaya T; Harashima A; Nishimoto T; Ushio S
[Ad] Endereço:R&D Center, Hayashibara Co., Ltd., Okayama, Japan.
[Ti] Título:Effects of a non-cyclodextrin cyclic carbohydrate on mouse melanoma cells: Characterization of a new type of hypopigmenting sugar.
[So] Source:PLoS One;12(10):e0186640, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Cyclic nigerosyl nigerose (CNN) is a cyclic tetrasaccharide that exhibits properties distinct from other conventional cyclodextrins. Herein, we demonstrate that treatment of B16 melanoma with CNN results in a dose-dependent decrease in melanin synthesis, even under conditions that stimulate melanin synthesis, without significant cytotoxity. The effects of CNN were prolonged for more than 27 days, and were gradually reversed following removal of CNN. Undigested CNN was found to accumulate within B16 cells at relatively high levels. Further, CNN showed a weak but significant direct inhibitory effect on the enzymatic activity of tyrosinase, suggesting one possible mechanism of hypopigmentation. While a slight reduction in tyrosinase expression was observed, tyrosinase expression was maintained at significant levels, processed into a mature form, and transported to late-stage melanosomes. Immunocytochemical analysis demonstrated that CNN treatment induced drastic morphological changes of Pmel17-positive and LAMP-1-positive organelles within B16 cells, suggesting that CNN is a potent organelle modulator. Colocalization of both tyrosinase-positive and LAMP-1-positive regions in CNN-treated cells indicated possible degradation of tyrosinase in LAMP-1-positive organelles; however, that possibility was ruled out by subsequent inhibition experiments. Taken together, this study opens a new paradigm of functional oligosaccharides, and offers CNN as a novel hypopigmenting molecule and organelle modulator.
[Mh] Termos MeSH primário: Ciclodextrinas/farmacologia
Glucanos/farmacologia
Hipopigmentação/patologia
Melanoma Experimental/patologia
[Mh] Termos MeSH secundário: Animais
Western Blotting
Linhagem Celular Tumoral
Glucosamina/farmacologia
Imuno-Histoquímica
Lisossomos/efeitos dos fármacos
Lisossomos/metabolismo
Melaninas/biossíntese
Melanoma Experimental/metabolismo
Melanossomas/efeitos dos fármacos
Melanossomas/metabolismo
Camundongos
Monofenol Mono-Oxigenase/metabolismo
Pressão Osmótica
Estresse Fisiológico/efeitos dos fármacos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cyclodextrins); 0 (Glucans); 0 (Melanins); 0 (cyclic nigerosylnigerose); EC 1.14.18.1 (Monophenol Monooxygenase); N08U5BOQ1K (Glucosamine)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171019
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0186640



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