Characterization of Fonsecaea pedrosoi melanin.
J Gen Microbiol
; 137(4): 837-44, 1991 Apr.
Article
in En
| MEDLINE
| ID: mdl-1856679
The constituents of the melanin complex from mycelial forms of Fonsecaea pedrosoi were partially characterized. The pigment was mainly accumulated on large alkali-extractable, electron-dense cytoplasmic bodies (melanosomes) and, apparently, on the outer layer of the cell wall as external deposits within verrucose outgrowths. Using electron microscopy and Thiéry's periodate/thiosemicarbazide/silver proteinate staining method, glycogen-like particles were also detected at the periphery of the cells. Melanin constituents comprised aromatic and aliphatic/glycosidic structures with a predominance of the latter. Infrared spectra showed the presence of hydroxyl, carbonyl and carboxyl groups. The aliphatic/glycosidic moiety consisted of fatty acids and polysaccharides with protein, in a ratio protein/polysaccharide 1:15. Rhamnose, mannose, galactose and glucose (in the ratio 1:2:4:3.5) were the constituents of the polysaccharide. Lipid components included even-numbered, saturated and unsaturated fatty acids (in the ratio 2:1) ranging from C16 to C18. Palmitic and oleic acids were the prominent fatty acids. Aspartic and glutamic acids, leucine, glycine and alanine were the major amino acids. Non-pigmented cells of F. pedrosoi were studied for comparison with the pigmented forms: they did not accumulate acid-insoluble precursors of melanin.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Chromoblastomycosis
/
Mitosporic Fungi
/
Melanins
Limits:
Humans
Language:
En
Journal:
J Gen Microbiol
Year:
1991
Document type:
Article
Affiliation country:
Brazil
Country of publication:
United kingdom