Incorporation and binding of estrogens into melanin: comparison of mushroom and mammalian tyrosinases

Jacobsohn, Gert M.; Jacobsohn, Myra K.

doi:10.1016/0304-4165(92)90114-a

Cited by 18 publications

(11 citation statements)

References 16 publications

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“…We found that the HPLC analysis results for melanin particles derived from C. neoformans grown with K. aerogenes were more complex than the results for particles generated with dopamine alone and suspected that this reflected the additional incorporation of unidentified bacterially derived products. It this regard, it is noteworthy that many types of compounds, including steroids, can be incorporated into melanins during their synthesis, (10). TLC revealed the presence of soluble pigment, suggesting that some fraction of the melanin precursor did not polymerize after laccase oxidation.…”

Section: Discussionmentioning

confidence: 99%

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Induction by Klebsiella aerogenes of a Melanin-Like Pigment in Cryptococcus neoformans

Frasés¹,

Chaskes

Dadachova

et al. 2006

Appl Environ Microbiol

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While studying the interaction of Cryptococcus neoformans with Dictyostelium discoideum, we noticed that yeast colonies in agar with a feeder lawn of Klebsiella aerogenes were brown. This finding was intriguing because C. neoformans colonies are not pigmented unless they are provided with precursors for melanization. Strains of all C. neoformans serotypes produced brown pigment in response to K. aerogenes at 22, 30, and 37°C. Pigment production required fungal laccase and was suppressed by high concentrations of glucose. Treatment of brown cells with guanidinium isothiocyanate and hot concentrated HCl yielded particulate material that had the physical and chemical characteristics of melanins. No pigment formation was observed when C. neoformans was exposed to live Escherichia coli or heat-killed K. aerogenes. Analysis of K. aerogenes supernatants revealed the presence of dopamine, which can be a substrate for melanin synthesis by C. neoformans. Our findings illustrate a remarkable interaction between a pathogenic fungus and a gram-negative bacterium, in which the bacterium produces a substrate that promotes fungal melanization. This observation provides a precedent that could explain the source of a substrate for C. neoformans melanization in the environment.

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Section: Discussionmentioning

confidence: 99%

“…To measure fungus-derived pigment accumulation in liquid cultures, 10 4 cells/ml of C. neoformans and K. aerogenes were incubated in liquid SM medium at 22°C for 5 days, and the medium was collected by centrifugation and filtered. The absorbance spectrum was determined, and the maximal signal was observed at a wavelength of 405 nm.…”

Section: Mediamentioning

confidence: 99%

Induction by Klebsiella aerogenes of a Melanin-Like Pigment in Cryptococcus neoformans

Frasés¹,

Chaskes

Dadachova

et al. 2006

Appl Environ Microbiol

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“…Therefore, use of tyrosinase for screening of tyrosinase inhibitors may depend on the purity of the enzyme as well as the assay conditions. It has been pointed out that MT has different enzymatic and physical properties compared to the human enzyme and extrapolation of data using MT may not be transferrable to reactions found in humans [13,14]. …”

Section: Introductionmentioning

confidence: 99%

Variations in IC50 Values with Purity of Mushroom Tyrosinase

Neeley

Fritch

Fuller

et al. 2009

IJMS

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The effects of various inhibitors on crude, commercial and partially purified commercial mushroom tyrosinase were examined by comparing IC50 values. Kojic acid, salicylhydroxamic acid, tropolone, methimazole, and ammonium tetrathiomolybdate had relatively similar IC50 values for the crude, commercial and partially purified enzyme. 4-Hexylresorcinol seemed to have a somewhat higher IC50 value using crude extracts, compared to commercial or purified tyrosinase. Some inhibitors (NaCl, esculetin, biphenol, phloridzin) showed variations in IC50 values between the enzyme samples. In contrast, hydroquinone, lysozyme, Zn2+, and anisaldehyde showed little or no inhibition in concentration ranges reported to be effective inhibitors. Organic solvents (DMSO and ethanol) had IC50 values that were similar for some of the tyrosinase samples. Depending of the source of tyrosinase and choice of inhibitor, variations in IC50 values were observed.

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“…Mushroom tyrosinases have significant differences from human tyrosinases in catalysis mechanisms [8,31–33]. We have known that the catalysis of the human tyrosinase and mushroom tyrosinase have diverse mechanism reactions.…”

Section: Resultsmentioning

confidence: 99%

Biological Properties of Acidic Cosmetic Water from Seawater

Liao

Huang

Chiu

et al. 2012

IJMS

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This current work was to investigate the biological effects of acidic cosmetic water (ACW) on various biological assays. ACW was isolated from seawater and demonstrated several bio-functions at various concentration ranges. ACW showed a satisfactory effect against Staphylococcus aureus, which reduced 90% of bacterial growth after a 5-second exposure. We used cultured human peripheral blood mononuclear cells (PBMCs) to test the properties of ACW in inflammatory cytokine release, and it did not induce inflammatory cytokine release from un-stimulated, normal PBMCs. However, ACW was able to inhibit bacterial lipopolysaccharide (LPS)-induced inflammatory cytokine TNF-α released from PBMCs, showing an anti-inflammation potential. Furthermore, ACW did not stimulate the rat basophilic leukemia cell (RBL-2H3) related allergy response on de-granulation. Our data presented ACW with a strong anti-oxidative ability in a superoxide anion radical scavenging assay. In mass spectrometry information, magnesium and zinc ions demonstrated bio-functional detections for anti-inflammation as well as other metal ions such as potassium and calcium were observed. ACW also had minor tyrosinase and melanin decreasing activities in human epidermal melanocytes (HEMn-MP) without apparent cytotoxicity. In addition, the cell proliferation assay illustrated anti-growth and anti-migration effects of ACW on human skin melanoma cells (A375.S2) indicating that it exerted the anti-cancer potential against skin cancer. The results obtained from biological assays showed that ACW possessed multiple bioactivities, including anti-microorganism, anti-inflammation, allergy-free, antioxidant, anti-melanin and anticancer properties. To our knowledge, this was the first report presenting these bioactivities on ACW.

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Incorporation and binding of estrogens into melanin: comparison of mushroom and mammalian tyrosinases

Cited by 18 publications

References 16 publications

Induction by Klebsiella aerogenes of a Melanin-Like Pigment in Cryptococcus neoformans

Induction by Klebsiella aerogenes of a Melanin-Like Pigment in Cryptococcus neoformans

Variations in IC50 Values with Purity of Mushroom Tyrosinase

Biological Properties of Acidic Cosmetic Water from Seawater

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