Possible role of a peroxidative system in melanin synthesis inVerticillium

MacMillan, Paul C.; Brandt, Walter

doi:10.1007/bf02097462

Cited by 6 publications

(2 citation statements)

References 6 publications

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“…Brandt and his associates (Brandt, 1962(Brandt, , 1964(Brandt, , 1965Brandt & Reese, 1964;MacMillan & Brandt, 1966) have clarified some of the events leading to microsclerotial formation but nothing is known about the biochemistry of vegetative development in this organism.…”

Section: Introductionmentioning

confidence: 99%

Structure and Composition of Walls of the Yeast Form of Verticillium albo-atrum

Wang

Bartnicki-García

1970

Journal of General Microbiology

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Walls of the yeast form of Verticillium albo-atrum showed a granular appearance on the outer surface. The granular components could be extracted by alkali, revealing a fibrillar wall fabric. A region of circularly oriented microfibrils with a minute central ' orifice ' was commonly found at one of the cell poles and probably represented a bud scar. The material dissolved by alkali was a heteropolysaccharide-protein complex containing mannose, galactose, glucose, glucuronic acid, glucosamine and the common range of amino acids. The alkali-insoluble microfibrillar network was made of a Plinked glucan and chitin. The glucan was digested by endo-P-glucanases yielding glucose, P-I ~-1inked glucose oligomers and cellobiose, but no evidence for cellulose was found. Most of the glucan was also soluble in hot acid. The acidinsoluble glucan (hydroglucan) contained p-I ,6-links. Acid treatment produced coarse microfibrils resembling those in Saccharomyces cerevisiae walls * treated similarly. The hydroglucan was soluble in alkali leaving an insoluble microfibrillar network composed mainly of chitin. A small amount of lipid (2.7 to 3.473, mostly of the bound type, and traces of phosphate were also found.

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Section: Introductionmentioning

confidence: 99%

Structure and Composition of Walls of the Yeast Form of Verticillium albo-atrum

Wang

Bartnicki-García

1970

Journal of General Microbiology

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“…Peroxidase (donor: hydrogen-peroxide oxidoreductase, EC 1.11.1.7) has also been observed to catalyze the oxidation of DOPA and other phenolic compounds to melanin (11,29). This enzyme uses H202 rather than molecular oxygen as a hydrogen acceptor and is inhibited by catalase (29).…”

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confidence: 99%

Production of Diagnostic Pigment by Phenoloxidase Activity of Cryptococcus neoformans

Shaw

Kapica

1972

Applied Microbiology

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Cryptococcus neoformans produces brown pigmented colonies when grown on agar media made from an extract of potatoes and carrots, broad beans (Vicia faba), or Guizotia abyssinica seeds. Since other yeasts do not produce the pigment, these media are useful as differential isolation media for C. neoformans. Similar specific pigment was produced by C. neoformans on chemically defined agar media which contained six different substrates of phenoloxidase (o-diphenol: oxygen oxidoreductase EC 1.10.3.1) an enzyme which catalyses the oxidation of o-diphenols to melanin. Substrates were incorporated singly into the media and included L-3,4-dihydroxyphenylalanine (L-DOPA), chlorogenic acid, protocatechuic acid, catechol, norepinephrine, and 3-hydroxytyramine hydrochloride (dopamine). No pigment was produced on media without substrate. Phenoloxidase activity in (NH,)2SO, precipitates of C. neoformans cell-free extract was assayed by measuring increases in absorbance at 480 nm produced in solutions of L-DOPA. This reaction showed oxygen uptake and was effectively inhibited by copper chelators, but not by catalase. The enzyme also oxidized the five other substrates which induced pigment formation. Electron micrographs of cells incubated in L-DOPA showed deposition of the pigment in the cell wall.

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Ultrastructural cytochemistry of the diaminobenzidine reaction in the aquatic fungus Entophlyctis variabilis

Powell

1977

Arch. Microbiol.

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Possible role of a peroxidative system in melanin synthesis inVerticillium

Cited by 6 publications

References 6 publications

Structure and Composition of Walls of the Yeast Form of Verticillium albo-atrum

Structure and Composition of Walls of the Yeast Form of Verticillium albo-atrum

Production of Diagnostic Pigment by Phenoloxidase Activity of Cryptococcus neoformans

Ultrastructural cytochemistry of the diaminobenzidine reaction in the aquatic fungus Entophlyctis variabilis

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