Generation of superoxide during the enzymatic action of tyrosinase

Koga, Satoshi; Nakano, Minoru; Tero‐Kubota, Shozo

doi:10.1016/0003-9861(92)90032-r

Cited by 55 publications

(38 citation statements)

References 23 publications

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“…However, it is highly conceivable that the phagocytic potential of human melanocytes (Dell'Angelica et al, 2000; Koga et, 1992;Le Poole et al, 1993) underlies the potent phagocytic activity of human metastatic melanoma cells that we have shown in this study. In fact, in the present report we compare phagocytic activity of metastatic melanoma cells with the phagocytic activity exerted by professional phagocytic cells, ie, by human primary macrophages.…”

Section: Discussionmentioning

confidence: 78%

“…This evidence is supported by the presence of an acidic pH, hydrolases, and acidic phosphatases in these organelles, as well as by their expression of some lysosomal-associated proteins (Lamp) (Dell'Angelica et al, 2000). Moreover, during melanogenesis, melanoma cells (similar to professional phagocytes) increase their amount of tyrosinase-produced superoxide anion (Koga et al, 1992).…”

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confidence: 86%

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Potent Phagocytic Activity Discriminates Metastatic and Primary Human Malignant Melanomas: A Key Role of Ezrin

Lugini

Lozupone

Matarrese

et al. 2003

Laboratory Investigation

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SUMMARY:Features of phagocytosis have been observed in human tumors, but the phagocytic apparatus of tumor cells and the mechanism(s) underlying this phenomenon have yet to be defined. To address the phenomenon of phagocytosis, its underlying mechanism(s), and its possible role in tumor biology, we used human melanoma cells as a prototypic model. Our results showed that a process of phagocytosis of apoptotic cells occurs in vivo in human melanoma. This finding was consistent with evidence that human melanoma cells in vitro express all of the known lysosomal and phagocytic markers on their cytoplasmic vesicles and that a process of phagocytosis occurs in these vesicles. However, exclusively human melanoma cells deriving from metastatic lesions possess an efficient phagocytic machinery responsible for a macrophage-like activity against latex beads, yeast, and apoptotic cells of different origins, which was comparable to that of human primary macrophages. Moreover, the actin-binding protein ezrin was expressed on phagocytic vacuoles of melanoma cells and of cells deriving from a human adenocarcinoma; both treatment with cytochalasin B and specific inhibition of ezrin synthesis strongly affected the phagocytic activity of melanoma cells. This suggests that the association with the actin cytoskeleton is a crucial requirement for the development of this phenomenon. Hence our data provide evidence for a potent phagocytic activity exerted by metastatic melanoma cells possibly involved in determining the level of aggressiveness of human melanoma. This suggests that the assessment of phagocytic activity may be exploited as a new tool to evaluate the malignancy of human melanoma. Moreover, our data suggest that gene therapy or drug treatments aimed at inhibiting actin assembly to the phagosomal membranes may be proposed as a new strategy for the control of tumor aggressiveness. (Lab Invest 2003, 83:1555-1567.

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Section: Discussionmentioning

confidence: 78%

mentioning

confidence: 86%

Potent Phagocytic Activity Discriminates Metastatic and Primary Human Malignant Melanomas: A Key Role of Ezrin

Lugini

Lozupone

Matarrese

et al. 2003

Laboratory Investigation

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“…It results in a continuous generation of ROS all along the process of melanogenesis: H 2 O 2 during its early stages [17] but also during the redox cycling from indoles to quinones [18], hydroxyl radicals and superoxide anion due to the catalytic activity of tyrosinase [19]. In addition, oxidative intermediates including reactive quinones, which are cytotoxic to proteins and DNA in the cells, are generated during melanogenesis [15].…”

Section: Influence Of the Melanogenesis On The Redox Status Of Melanomentioning

confidence: 99%

Melanocytes and Oxidative Stress

Diehl¹

2014

Pigmentary Disorders

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“…Although involvement of copper and generation of O 2 · • -are analogous to tyrosinase which oxidizes tyrosine and polyphenols with concomitant release of O 2 · • - (Koga et al, 1992), the roles played by H 2 O 2 are largely different. While the reaction studied here requires the presence of H 2 O 2 as a co-factor (or co-substrate) (Figs.…”

Section: Tyramine-dependent and Tyrosine-dependent Oxidative Burstmentioning

confidence: 99%

Copper-Binding Peptides from Human Prion Protein and Newly Designed Peroxidative Biocatalysts

Kagenishi

Yokawa

Kadono

et al. 2011

Zeitschrift Für Naturforschung C

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A previous work suggested that peptides from the histidine-containing copper-binding motifs in human prion protein (PrP) function as peroxidase-like biocatalysts catalyzing the generation of superoxide anion radicals in the presence of neurotransmitters (aromatic monoamines) and phenolics such as tyrosine and tyrosyl residues on proteins. In this study, using various phenolic substrates, the phenol-dependent superoxide-generating activities of PrP-derived peptide sequences were compared. Among the peptides tested, the GGGTH pentapeptide was shown to be the most active catalyst for phenol-dependent reactions. Based on these results, we designed a series of oligoglycyl-histidines as novel peroxidative biocatalysts, and their catalytic performances including kinetics, heat tolerance, and freezing tolerance were analysed.

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Generation of superoxide during the enzymatic action of tyrosinase

Cited by 55 publications

References 23 publications

Potent Phagocytic Activity Discriminates Metastatic and Primary Human Malignant Melanomas: A Key Role of Ezrin

Potent Phagocytic Activity Discriminates Metastatic and Primary Human Malignant Melanomas: A Key Role of Ezrin

Melanocytes and Oxidative Stress

Copper-Binding Peptides from Human Prion Protein and Newly Designed Peroxidative Biocatalysts

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