Antioxidant function of melanin in black fungi

Jacobson, Eric S.; Hove, E. L.; Emery, H S

doi:10.1128/iai.63.12.4944-4945.1995

Cited by 104 publications

(49 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Melanized cryptococcal cells were also more resistant to oxygen-and nitrogen-derived radicals than non-melanized cells (Wang and Casadevall, 1994c;Wang et al, 1995). DHN melanin in E. dermatitidis and A. alternata protects against permanganate and hypochlorite (Jacobson et al, 1995). As with C. neoformans (Jacobson and Tinnell, 1993), melanin did not limit the effects of H 2 O 2 , a weak fungicide, on E. dermatitidis cells (Jacobson et al, 1995).…”

Section: Protection Against Oxidantsmentioning

confidence: 92%

“…DHN melanin in E. dermatitidis and A. alternata protects against permanganate and hypochlorite (Jacobson et al, 1995). As with C. neoformans (Jacobson and Tinnell, 1993), melanin did not limit the effects of H 2 O 2 , a weak fungicide, on E. dermatitidis cells (Jacobson et al, 1995). Pigmented E. dermatitidis were protected against neutrophil oxidative burst due to polymerized melanin, and not carotenoids or the melanin precursor scytoalone (Schnitzler et al, 1999).…”

Section: Protection Against Oxidantsmentioning

confidence: 93%

See 1 more Smart Citation

The contribution of melanin to microbial pathogenesis

Nosanchuk

Casadevall

2003

Cellular Microbiology

554

454

View full text Add to dashboard Cite

SummaryMelanins are enigmatic pigments that are produced by a wide variety of microorganisms including several species of pathogenic bacteria, fungi and helminthes. The study of melanin is difficult because these pigments defy complete biochemical and structural analysis. Nevertheless, the availability of new reagents in the form of monoclonal antibodies and melaninbinding peptides, combined with the application of various physical techniques, has provided insights into the process of melanization. Melanization is important in microbial pathogenesis because it has been associated with virulence in many microorganisms. Melanin appears to contribute to virulence by reducing the susceptibility of melanized microbes to host defence mechanisms. However, the interaction of melanized microbes and the host is complex and includes immune responses to melanin-related antigens. Production of melanin has also been linked to protection against environmental insults. Interference with melanization is a potential strategy for antimicrobial drug and pesticide development. The process of melanization poses fascinating problems in cell biology and provides a type of pathogenic strategy that is common to highly diverse pathogens.

show abstract

Section: Protection Against Oxidantsmentioning

confidence: 92%

Section: Protection Against Oxidantsmentioning

confidence: 93%

The contribution of melanin to microbial pathogenesis

Nosanchuk

Casadevall

2003

Cellular Microbiology

554

454

View full text Add to dashboard Cite

show abstract

“…The precise means by which melanin may contribute to virulence is only partially understood. Several studies have shown that melanin can act as a scavenger of reactive oxygen species that are produced during host defence reactions (Fels et al, 1987;Wang & Casadevall, 1994;Jacobson et al, 1995;Wang et al, 1995;Schnitzler et al, 1999). Melanized cells are less sensitive to killing by reactive oxygen species than are unmelanized mutants or other unmelanized cells.…”

Section: How Pathogens Deal With Host Defence Responsesmentioning

confidence: 99%

Molecular mechanisms of pathogenicity: how do pathogenic microorganisms develop cross-kingdom host jumps?

et al. 2007

View full text Add to dashboard Cite

It is common knowledge that pathogenic viruses can change hosts, with avian influenza, the HIV, and the causal agent of variant Creutzfeldt-Jacob encephalitis as well-known examples. Less well known, however, is that host jumps also occur with more complex pathogenic microorganisms such as bacteria and fungi. In extreme cases, these host jumps even cross kingdom of life barriers. A number of requirements need to be met to enable a microorganism to cross such kingdom barriers. Potential cross-kingdom pathogenic microorganisms must be able to come into close and frequent contact with potential hosts, and must be able to overcome or evade host defences. Reproduction on, in, or near the new host will ensure the transmission or release of successful genotypes. An unexpectedly high number of cross-kingdom host shifts of bacterial and fungal pathogens are described in the literature. Interestingly, the molecular mechanisms underlying these shifts show commonalities. The evolution of pathogenicity towards novel hosts may be based on traits that were originally developed to ensure survival in the microorganism's original habitat, including former hosts.

show abstract

“…Melanized Cryptococcus neoformans cells had an approximately 10fold survival rate than the nonmelanized cells when exposed to oxygen and nitrogen free radicals [9]. Melanotic strains of Wangiella dermatitidis and Alternaria alternata can neutralize more oxidant and withstand higher concentrations of permanganate and hypochlorite than albino strains did [25].…”

Section: Antioxidant Activity Of the Hm Melaninmentioning

confidence: 99%

Identification and antioxidant activity of melanin isolated from Hypoxylon archeri, a companion fungus of Tremella fuciformis

Shan

Yang

et al. 2008

J. Basic Microbiol.

View full text Add to dashboard Cite

Melanin produced by Hypoxylon archeri, a companion fungus of Tremella fuciformis, was purified from the submerged culture medium and designated as HM. Ultraviolet-visible and FTIR spectra of the purified HM showed significant similarities with those of the synthesized melanin derived from tyrosine. Thus, the HM melanin was identified to be derived from the precursor molecule of tyrosine or dihydroxyphenylalanine (DOPA). The antioxidant activity of HM melanin, synthetic melanin and vitamin C were compared by inhibition of the oxidation of 5-thio-2-nitrobenzoic acid (TNB) caused by hypochlorous acid (HOCl) and hydrogen peroxide (H(2)O(2)). The HM melanin is likely to be more efficient eliminating oxygen free radicals generated by H(2)O(2) than by HOCl. At a concentration of 100 mg x l(-1), the HM melanin protected 80.95% of TNB oxidation by H(2)O(2), slightly higher than the synthetic melanin. Inhibition curves as a function of time also revealed the HM melanin was a more efficient inhibitor of H(2)O(2) oxidation with an average TNB (TNB(acr)) consumption rate of 0.0553 mmol l(-1 ) x min(-1 )during the inhibition phase. Therefore, HM melanin is an efficient scavenger of peroxide free radicals.

show abstract

Antioxidant function of melanin in black fungi

Cited by 104 publications

References 20 publications

The contribution of melanin to microbial pathogenesis

The contribution of melanin to microbial pathogenesis

Molecular mechanisms of pathogenicity: how do pathogenic microorganisms develop cross-kingdom host jumps?

Identification and antioxidant activity of melanin isolated from Hypoxylon archeri, a companion fungus of Tremella fuciformis

Contact Info

Product

Resources

About