The Cell Wall Polysaccharides of Candida Albicans: Glucan, Mannan, and Chitin

Abstract

Cells of Candida albicans, a pathogenic yeast, have been show11 to contain, in addition to chitin, a glucan ([ff]~ -30") and a mannan ( [ a ]~ +78") i n the approximate ratio of 1.00:0.84. The two polysaccharides were easily distinguishable by 1110ving boundary electrophoresis in borate butler and were separated froin each other by fractionation of their copper complexes. i\/Iethylation and hydrolysis of the glucan yielded the following 0-methyl ethers of D-glucose: 3,3,4,6-tetra-0-methyl ('7 moles); 2,3,4-tri-0-nlethyl (13 moles); 2,4,8-tri-0-methyl (trace); 2,4-di-0-methyl (8 ~noles); and 2-0-methyl (1 mole). It was concluded that the glucan was a highly branched polysaccharide containing 0 1 + 8 and 0 1 + 3 linked residues. Periodate oxidation of the glucan supported this conclusion.Methylation and hydrolysis of the mannan yielded the following 0-methyl ethers of D-mannose: 2,3,4,8-tetra-0-methyl (1.65 moles); 3,4,6-tri-0-methyl (1.00 mole); 2,3,6-tri-0-methyl (0.18 mole); 3,4-di-0-methyl (1.90 moles). The mannan was therefore a highly branched polysaccharide with short chains of a 1 + 2 linked mannose residues joined together by a 1 + 8 linkages. Results of periodate oxidation agreed with this structure.The diaerences between these two polysaccharides and g l~~c a n s and mannans found in other yeasts are discussed.Structural investigations of polysaccharide components of yeasts have been limited, with only one exception, to those in bakers' yeast (Saccharo?lzyces cerevisiae) and there are a number of reports dealing with the glucan (1-4) and mannan (5-7) that occur in this species. The only report dealing with structures of polysaccharides from other yeast species appears to be that by Gorin and Perlin ( 8 ) which described a mannan produced by S n c c h a r o m y c e s r o u x i i . There have been other publications on the composition of cell \valls of jqeasts (9-18) and some of these (13-18) have dealt with species other than S a c c h n r o m y c e s cerevisiae. However, these papers were concerned pri~iiarily with examination of fractions of yeast cell walls by X-ray diffraction, electrophoresis, and chromatography of hydrolyzates; structures of pol>-saccharides were not investigated and co~lstituent sugars were identified only by paper chromatography. The identification of D-al-abinose as a constituent of polysaccharides found in N o c a r d i a a s t e r o i d e s ( 1 0 ) and I l f y c o b a c t e r i u m t~l b e r c z~l o s i s(20) has shown that sugars can occur in unusual configurations in microorganisms. For this reason the distinction of enantionlorphic forms of naturally occurring sugars is of considerable significance and such distinction cannot be made by paper chromatography. I t was therefore of interest to examine the polysaccharides of another species of yeast, C. albica?zs, to see if they differed in structure or constitue~lt sugars fro111 the polrsaccharides of bakers' yeast. In addition to this a report that the polysaccharides of C. n l b i c a n s , a pathogenic yeast, are ...

Immunological and Toxic Differences Between Mouse-Virulent and Mouse-Avirulent Candida Albicans

“…The endotoxinlike nature of the complex haptens extracted from the mouse-virulent strains became apparent clinically during the immunization procedures, as reported cursorily earlier (Isenberg, Allerhand, and Berkman, 1963 (Jonsen, Rasch, and Strand, 1955;Jonsen, 1955;Bishop, Blank, and Gardner, 1960) and the observations that virulence of this yeast is associated with a toxic principle (Salvin, 1952;Mourad and Friedman, 1961;Hasenclever and Mitchell, 1962a, b;Roth and Murphy, 1957). The difference between the mouse-avirulent and the mouse-virulent variants is obvious from the immunological reactions with agglutinations, precipitations, and antibody-absorption studies.…”

Mechanisms of Attachment of Neutrophils to Candida albicans Pseudohyphae in the Absence of Serum, and of Subsequent Damage to Pseudohyphae by Microbicidal Processes of Neutrophils In Vitro

“…Another possibility is that of a cell receptor for mannose (5), because the Candida cell wall has a high content of mannose, primarily in the form of mannans (6,7). The Candida cell wall also contains glucans, glucomannans, perhaps chitin, and mannoproteins (7)(8)(9)(10), which might be involved in reactions with surface receptors of neutrophils. Our previous studies indicated that only live and not killed Candida interacted with neutrophils (1), suggesting that the material which is recognized by neutrophils is either labile or loosely attached to the Candida surface.…”

Effect of CAWS, a Mannoprotein-.BETA.-glucan Complex of Candida albicans, on Leukocyte, Endothelial Cell, and Platelet Functions in Vitro.

“…Cells were suspended at a density of 5ϫ10 4 and 1ϫ10 5 cells/ml and left for 2 h to adhere to the culture plate. They were then cultured with CAWS or sonifilan (SPG) (Kaken Pharmaceutical, Tokyo) (25-500 mg/ml) for 24 h in a 5% CO 2 incubator at 37°C.…”

“…The major polysaccharides of cell wall were b-1,3 and b-1,6-branched glucan (b-glucan), chitin, and mannan covalently associated with proteins (mannoprotein). [3][4][5][6][7][8] In a series of studies, we used a chemically defined liquidmedium to culture Candida spp. and obtained a water-soluble high molecular weight fraction, termed CAWS.…”