PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 8908594-4 1996 The partial inhibitions by catalase of the auto-oxidations and tyrosinase- and peroxidase-mediated oxidations of DHI and DHICA provide additional evidence of an endogenous origin of H2O2 during the final stages of eumelanogenesis. Hydrogen Peroxide 182-186 tyrosinase Homo sapiens 63-73 12899964-1 2003 The development and characterisation of a new biosensor for hydroperoxides is described, which is obtained by combining an oxygen gas diffusion amperometric electrode and two immobilized enzymes (peroxidase and tyrosinase) working in parallel and competing for the same substrate (catechol). Hydrogen Peroxide 60-74 tyrosinase Homo sapiens 211-221 10643998-5 1999 Finally, the role of tyrosinase, TRP-1 and TRP2 is discussed in association with oxidative stress specifically related to hydrogen peroxide. Hydrogen Peroxide 122-139 tyrosinase Homo sapiens 21-31 15206795-6 2003 We observed that both enzymes converted this substrate to melanin and that peroxidase, in the presence of hydrogen peroxide, was much more effective than tyrosinase in catalysing the oxidative polymerization of 5-hydroxytryptophan, with the formation of insoluble black melanin-like pigments. Hydrogen Peroxide 106-123 tyrosinase Homo sapiens 154-164 11368547-10 2001 Extents of oxygen consumption and H(2)O(2) production during the reaction of Cr(VI) with enzymatically generated 1 and N-acetyl-DOPA (from the reaction of Tyr and N-acetyl-Tyr with tyrosinase, respectively) were correlated with the DNA cleaving abilities of the products of these reactions. Hydrogen Peroxide 34-42 tyrosinase Homo sapiens 181-191 1659822-1 1991 Tyrosinase (EC 1.14.18.1)/O2, ceruloplasmin (human type X)/O2, and peroxidase (EC 1.11.1.7)/H2O2 oxidized the endogenous central nervous system alkaloid salsolinol (SAL) at physiological pH. Hydrogen Peroxide 92-96 tyrosinase Homo sapiens 0-10 8433009-0 1993 Hydrogen peroxide as an inducer of elevated tyrosinase level in melanoma cells. Hydrogen Peroxide 0-17 tyrosinase Homo sapiens 44-54 8433009-10 1993 It is concluded that hydrogen peroxide, formed by the systems, accounts for the elevation of tyrosinase level. Hydrogen Peroxide 21-38 tyrosinase Homo sapiens 93-103 8433009-13 1993 On the basis of our findings, it is assumed that hydrogen peroxide is a regulator of tyrosinase in normal melanocytes and melanoma cells. Hydrogen Peroxide 49-66 tyrosinase Homo sapiens 85-95 1309977-5 1992 Since the addition of H2O2 and dopa to tyrosinase promotes the release of O2- and formation of dopachrome, the Cu(II)O2-Cu(I) complex could be formed as a intermediate (an active form of tyrosinase); [Cu(II)]2 + H2O2 in equilibrium Cu(I)O2-Cu(II) + 2H+. Hydrogen Peroxide 22-26 tyrosinase Homo sapiens 39-49 1309977-5 1992 Since the addition of H2O2 and dopa to tyrosinase promotes the release of O2- and formation of dopachrome, the Cu(II)O2-Cu(I) complex could be formed as a intermediate (an active form of tyrosinase); [Cu(II)]2 + H2O2 in equilibrium Cu(I)O2-Cu(II) + 2H+. Hydrogen Peroxide 22-26 tyrosinase Homo sapiens 187-197 1309977-5 1992 Since the addition of H2O2 and dopa to tyrosinase promotes the release of O2- and formation of dopachrome, the Cu(II)O2-Cu(I) complex could be formed as a intermediate (an active form of tyrosinase); [Cu(II)]2 + H2O2 in equilibrium Cu(I)O2-Cu(II) + 2H+. Hydrogen Peroxide 212-216 tyrosinase Homo sapiens 39-49 1309977-5 1992 Since the addition of H2O2 and dopa to tyrosinase promotes the release of O2- and formation of dopachrome, the Cu(II)O2-Cu(I) complex could be formed as a intermediate (an active form of tyrosinase); [Cu(II)]2 + H2O2 in equilibrium Cu(I)O2-Cu(II) + 2H+. Hydrogen Peroxide 212-216 tyrosinase Homo sapiens 187-197 1653610-4 1991 Hydrogen peroxide was shown to be a competitive inhibitor of tyrosinase when L-tyrosine was the substrate. Hydrogen Peroxide 0-17 tyrosinase Homo sapiens 61-71 27342394-5 2016 Thus, for tyrosinase to act on this compound, a mechanism to generate Eox in the medium is required, which can be achieved by means of hydrogen peroxide or ascorbic acid. Hydrogen Peroxide 135-152 tyrosinase Homo sapiens 10-20 1748819-3 1991 Hydrogen peroxide functions as a reversible inhibitor of human tyrosinase with a KI of 8 X 10(-6) M. Also, hydrogen peroxide undergoes photochemical reduction yielding highly reactive hydroxyl radicals (OH.) Hydrogen Peroxide 0-17 tyrosinase Homo sapiens 63-73 1748819-3 1991 Hydrogen peroxide functions as a reversible inhibitor of human tyrosinase with a KI of 8 X 10(-6) M. Also, hydrogen peroxide undergoes photochemical reduction yielding highly reactive hydroxyl radicals (OH.) Hydrogen Peroxide 107-124 tyrosinase Homo sapiens 63-73 1899444-4 1991 The results show that extracellular hydrogen peroxide is a mediator of both the tyrosinase-stimulating and cytotoxic actions of dopac. Hydrogen Peroxide 36-53 tyrosinase Homo sapiens 80-90 2114224-2 1990 Both the formation of hydrogen peroxide and that of 8-OHdG in DNA was significantly decreased when catalase or tyrosinase was added to the smoke condensates, and this also occurred when pure hydroquinone or catechol, two major constitutes in cigarette smoke, was used instead of smoke condensate. Hydrogen Peroxide 22-39 tyrosinase Homo sapiens 111-121 6203305-4 1984 Thus, oxygen radicals and/or hydrogen peroxide may contribute to the inactivation of human tyrosinase by cysteine. Hydrogen Peroxide 29-46 tyrosinase Homo sapiens 91-101 28956555-4 2017 The nontoxic probe Tyro-1 provides information about H2O2-mediated upregulation of tyrosinase through cellular imaging. Hydrogen Peroxide 53-57 tyrosinase Homo sapiens 83-93 1849012-1 1991 The ability of the peroxidase/H2O2 system to promote the oxidative polymerization of 5,6-dihydroxyindole (DI) and 5,6-dihydroxyindole-2-carboxylic acid (DICA) to melanin pigments was investigated in comparison with tyrosinase. Hydrogen Peroxide 30-34 tyrosinase Homo sapiens 215-225 32122653-8 2020 In SS B16 melanoma, exogenous non-toxic 100 muM H2O2 super-induces the ratio of tyrosinase to HIF1alpha. Hydrogen Peroxide 48-52 tyrosinase Homo sapiens 80-90 32122653-9 2020 However, co-treatment of SS-B16 cells with SNP plus exogenous H2O2, partly increases PARP cleavage by reciprocally decreasing tyrosinase expression. Hydrogen Peroxide 62-66 tyrosinase Homo sapiens 126-136 29663060-4 2018 Tyrosinase (TYR) can catalyze adrenaline to generate H2O2, and additionally oxidize the adrenaline to adrenaline quinone. Hydrogen Peroxide 53-57 tyrosinase Homo sapiens 0-10 29663060-4 2018 Tyrosinase (TYR) can catalyze adrenaline to generate H2O2, and additionally oxidize the adrenaline to adrenaline quinone. Hydrogen Peroxide 53-57 tyrosinase Homo sapiens 12-15 27692799-8 2016 In the melanocytes co-cultured with H2O2-treated fibroblasts, the expression of tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1), and KIT was increased, whereas TYRP2 and microphthalmia-associated transcription factor showed no change. Hydrogen Peroxide 36-40 tyrosinase Homo sapiens 80-90 27692799-8 2016 In the melanocytes co-cultured with H2O2-treated fibroblasts, the expression of tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1), and KIT was increased, whereas TYRP2 and microphthalmia-associated transcription factor showed no change. Hydrogen Peroxide 36-40 tyrosinase Homo sapiens 92-95 26086354-9 2015 The tyrosinase inactivation involves two different pathways: (i) a photosensitization process and (ii) the oxidation of the enzyme by the hydrogen peroxide produced during the photooxidation of PteGlu and its photoproduct. Hydrogen Peroxide 138-155 tyrosinase Homo sapiens 4-14 26176355-4 2015 For tyrosinase to act in this way, the Eox form (oxy-tyrosinase) must be present in the reaction medium, which can be brought about by (a) hydrogen peroxide, (b) ascorbic acid, or (c) catalytic concentrations of o-diphenol and a reductant (NADH) to maintain it constant. Hydrogen Peroxide 139-156 tyrosinase Homo sapiens 4-14 26176355-4 2015 For tyrosinase to act in this way, the Eox form (oxy-tyrosinase) must be present in the reaction medium, which can be brought about by (a) hydrogen peroxide, (b) ascorbic acid, or (c) catalytic concentrations of o-diphenol and a reductant (NADH) to maintain it constant. Hydrogen Peroxide 139-156 tyrosinase Homo sapiens 53-63 25625855-5 2015 Furthermore, H2O2 inhibited tyrosinase export from the ER and decreased expression levels of tyrosinase; however, quercetin was found to attenuate the effects induced by H2O2. Hydrogen Peroxide 13-17 tyrosinase Homo sapiens 28-38 25625855-5 2015 Furthermore, H2O2 inhibited tyrosinase export from the ER and decreased expression levels of tyrosinase; however, quercetin was found to attenuate the effects induced by H2O2. Hydrogen Peroxide 13-17 tyrosinase Homo sapiens 93-103 25625855-6 2015 In conclusion, the results of the present study confirmed the hypothesis that H2O2 induced ER dilation and hindered functional tyrosinase export from the ER of melanocytes. Hydrogen Peroxide 78-82 tyrosinase Homo sapiens 127-137 26692814-7 2015 Our observations are explained in terms of a catalase-cycled kinetic mechanism based on the binding of H2O2 to the axial position of one of the active copper sites of the oxy-Tyr during the catalase cycle to produce deoxy-Tyr. Hydrogen Peroxide 103-107 tyrosinase Homo sapiens 175-178 26692814-7 2015 Our observations are explained in terms of a catalase-cycled kinetic mechanism based on the binding of H2O2 to the axial position of one of the active copper sites of the oxy-Tyr during the catalase cycle to produce deoxy-Tyr. Hydrogen Peroxide 103-107 tyrosinase Homo sapiens 222-225 24842617-5 2014 However, in the presence of hydrogen peroxide, met-tyrosinase (inactive on hydroquinone) is transformed into oxy-tyrosinase, which is active on HQ. Hydrogen Peroxide 28-45 tyrosinase Homo sapiens 51-61 24842617-5 2014 However, in the presence of hydrogen peroxide, met-tyrosinase (inactive on hydroquinone) is transformed into oxy-tyrosinase, which is active on HQ. Hydrogen Peroxide 28-45 tyrosinase Homo sapiens 113-123 24842617-8 2014 The formation of HHQ during the action of tyrosinase on HQ is demonstrated by means of high performance liquid chromatography mass spectrometry (HPLC-MS) by using hydrogen peroxide and high ascorbic acid concentrations. Hydrogen Peroxide 163-180 tyrosinase Homo sapiens 42-52 23523934-3 2013 Treatment with 1mM H2O2 increased the cellular melanin content; the expression of PAH, TYR, and MITF; and the phosphorylation of CREB in B16F10 and SK-Mel-2 cells. Hydrogen Peroxide 19-23 tyrosinase Homo sapiens 87-90 20958268-8 2011 Tyrosinase activity is impaired by excess H2O2 through oxidation of methionine residues in this key melanogenic enzyme. Hydrogen Peroxide 42-46 tyrosinase Homo sapiens 0-10 24317051-0 2013 Hydrogen peroxide helps in the identification of monophenols as possible substrates of tyrosinase. Hydrogen Peroxide 0-17 tyrosinase Homo sapiens 87-97 24317051-4 2013 The fact that E(ox) can be formed from Em with hydrogen peroxide can be used to help identify whether a monophenol is a substrate of tyrosinase. Hydrogen Peroxide 47-64 tyrosinase Homo sapiens 133-143 22572404-7 2012 RESULTS: This study demonstrated that tyrosinase was activated by low concentrations of H(2)O(2) (<=0.3 mM); however, this activity was downregulated by high concentrations of H(2)O(2) (>0.3 mM). Hydrogen Peroxide 88-96 tyrosinase Homo sapiens 38-48 22572404-7 2012 RESULTS: This study demonstrated that tyrosinase was activated by low concentrations of H(2)O(2) (<=0.3 mM); however, this activity was downregulated by high concentrations of H(2)O(2) (>0.3 mM). Hydrogen Peroxide 179-187 tyrosinase Homo sapiens 38-48 18688822-4 2008 The former type of reaction can be promoted by tyrosinase, the latter by peroxidases in the presence of H(2)O(2), which can be formed under oxidative stress conditions. Hydrogen Peroxide 104-112 tyrosinase Homo sapiens 47-57 20958953-8 2011 This article aims to focus on the effect of H(2)O(2)-redox homeostasis on hair follicle pigmentation via tyrosinase, its substrate supply and signal transduction as well as the role of methionine sulfoxide repair via methionine sulfoxide reductases A and B (MSRA and B). Hydrogen Peroxide 44-52 tyrosinase Homo sapiens 105-115 18177348-10 2008 Finally, we propose a novel mechanism involving H2O2 in the regulation of tyrosinase via p53 through transcription of hepatocyte nuclear factor 1alpha which in turn can also affect the POMC response. Hydrogen Peroxide 48-52 tyrosinase Homo sapiens 74-84 18324837-5 2008 The association of the (3)-functionalized Pt NPs or CdS NPs to a boronic acid monolayer-modified electrode enables the electrochemical transduction of TR activity by the Pt-NPs-electrocatalyzed reduction of H2O2 or the photoelectrochemical transduction of TR activity by the generation of photocurrents in the presence of triethanolamine as a sacrificial electron donor. Hydrogen Peroxide 207-211 tyrosinase Homo sapiens 151-153 18324837-5 2008 The association of the (3)-functionalized Pt NPs or CdS NPs to a boronic acid monolayer-modified electrode enables the electrochemical transduction of TR activity by the Pt-NPs-electrocatalyzed reduction of H2O2 or the photoelectrochemical transduction of TR activity by the generation of photocurrents in the presence of triethanolamine as a sacrificial electron donor. Hydrogen Peroxide 207-211 tyrosinase Homo sapiens 256-258 16723376-6 2006 The latter two analogs were more potent than the former, or alpha-MSH, in stimulating the activity of tyrosinase, thus melanogenesis, reducing apoptosis and release of hydrogen peroxide and enhancing repair of DNA photoproducts in melanocytes exposed to UV radiation (UVR). Hydrogen Peroxide 168-185 tyrosinase Homo sapiens 102-112 16950829-9 2006 Identification of the enzymes as tyrosinases was confirmed by the ability of lichen thalli or leachates derived by shaking lichens in distilled water to metabolize substrates such as L-dihydroxyphenylalanine (DOPA), tyrosine and epinephrine readily in the absence of hydrogen peroxide, the sensitivity of the enzymes to the inhibitors cyanide, azide and hexylresorcinol, activation by SDS and having typical tyrosinase molecular masses of approx. Hydrogen Peroxide 267-284 tyrosinase Homo sapiens 33-43 15007389-6 2004 In vitro mechanistic studies demonstrated that transfection of the Tyr(Cys) allele in a human squamous cell carcinoma cell line (NCI-H520) increases tyrosinase enzyme activity and confers resistance to hydrogen peroxide-induced oxidative DNA damage. Hydrogen Peroxide 202-219 tyrosinase Homo sapiens 67-70 15885091-0 2005 Production and utilization of hydrogen peroxide associated with melanogenesis and tyrosinase-mediated oxidations of DOPA and dopamine. Hydrogen Peroxide 30-47 tyrosinase Homo sapiens 82-92 15885091-2 2005 Catalase-treated reaction mixtures showed diminished rates of H(2)O(2) production during the autoxidation and tyrosinase-mediated oxidation of both diphenols. Hydrogen Peroxide 62-70 tyrosinase Homo sapiens 110-120 15885091-5 2005 Establishing by electrochemical methods the endogenous production H(2)O(2) in real time confirms recent reports, based in large part on the use of exogenous H(2)O(2), that tyrosinase can manifest both catalase and peroxidase activities. Hydrogen Peroxide 66-74 tyrosinase Homo sapiens 172-182 15778083-7 2005 Lastly, we demonstrate that the tyrosyl radicals generated by light or by the peroxidase/hydrogen peroxide system are not directly trapped by the tyrosinase but by the antioxidant orthodiphenol, L-dopa, accumulated in the steady-state of melanogenesis. Hydrogen Peroxide 89-106 tyrosinase Homo sapiens 146-156 15555584-0 2004 Regulation of tyrosinase by tetrahydropteridines and H2O2. Hydrogen Peroxide 53-57 tyrosinase Homo sapiens 14-24