Taxonomic group: fungi / Basidiomycota
(Phylum: Basidiomycota)
The structure was elucidated in this paperNCBI PubMed ID: 11779566Publication DOI: 10.1016/s0005-2736(01)00428-xJournal NLM ID: 0217513Publisher: Elsevier
Correspondence: puchkov
ibpm.serpukhov.su
Institutions: Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Russia, Research Center Borstel, Center for Medicine and Biosciences, Division of Biophysics, Borstel, Germany
The chemical composition of the mycocidal complex (formerly known as microcin) secreted by Cryptococcus humicola was investigated by chemical, mass spectrometric and nuclear magnetic resonance methods. The results indicate that the mycocidal complex is composed of glycolipids with a highly acetylated (up to five acetyl groups) cellobiose backbone [β-D-Glcp-(1'→4)-β-D-Glcp] linked to the ω-hydroxyl group of α,ω-dihydroxy palmitate [16:0-α,ω-di-OH] with an unsubstituted carboxyl group. The acyl chain forming aglycon can be replaced by [18:0-(α,ω-di-OH)], [18:0-(α,ω-1,ω-tri-OH)], and [18:0-(α,ω-2,ω-tri-OH)]. The complex has a comparatively high surface activity; 0.5 mg/ml of it reduced the surface tension of 0.1 M NaHCO(3) from 71 mN/m to 37 mN/m and interfacial tension against n-hexadecane from 39 mN/m to 10 mN/m. The critical micelle concentration of the complex at pH 4.0, determined by the fluorometric method with N-phenyl-1-naphthylamine as fluorescent probe and by the De Nouy ring method, was 20 μM (taking the average molecular mass of the complex to be 750); it did not depend on the presence of 100 mM KCl and was an order of magnitude higher at pH 7.0. By fluorescence resonance energy transfer spectroscopy with N-(7-nitro-2,1,3-benzoxadiazol-4-yl)-phosphatidylethanolamine as energy donor and N-(rhodamine B sulfonyl)-phosphatidylethanolamine as energy acceptor the complex was shown to intercalate into the liposomal lipid matrix. Primary lesions caused by the complex in planar lipid bilayers were revealed as short-living current fluctuations of a broad spectrum of amplitudes. The mycocidal effect of the complex is suggested to be associated with its detergent-like properties
permeability, mass spectrometry, nuclear magnetic resonance spectroscopy, detergent, Cryptococcus, yeast, cellobiose lipid, mycocidal effect, lipid membrane
Structure type: oligomer
Location inside paper: Fig. 2
Compound class: glycolipid
Contained glycoepitopes: IEDB_142488,IEDB_146664,IEDB_983931,SB_192,SB_61
Methods: 13C NMR, 1H NMR, NMR-2D, methylation, GLC-MS, ESI-MS, acid hydrolysis, GLC, extraction, FRET, acetylation, fluorescence spectroscopy, reduction, column chromatography, cell growth, evaporation, sonication, determination of surface tension, electrical measurements
Biological activity: cellobiose lipids secreted by C. humicola have mycocidal activity against a broad spectrum of both basidiomycetous and ascomycetous yeasts. Minimal inhibitory concentrations for the MC and nystatin assessed at the same experimental conditions were 5-10 μg/ml and and 1-5 μg/ml, respectively. FRET experiments on liposomes indicate that cellobiose lipids of the MC can intercalate into the lipid matrix. This intercalation results in permeabilization of the lipid bilayer that strongly differs from the effects of the ion carrier nonactin or the channel former nystatin
Comments, role: LIP is 2,16-dihydroxypalmitic acid or di- or trihydroxylstearic acid
NCBI Taxonomy refs (TaxIDs): 5417
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There is only one chemically distinct structure:
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(later renamed to: Vanrija humicola 9-6)