Glycoconjugate Journal (1992) 9:75-81 O-Glycosidically linked oligosaccharides from peptidorhamnomannans of Sporothrix schenckii LEILA M. LOPES-ALVES 1, LUCIA MENDON(~A-PREVIATO 2., BERNARD FOURNET 3, PIERRE DEGAND 4 and JOSE O. PREVIATO 2 1Depart. Biologia Celular e Gen~tica-UERJ, Rio de Janeiro, Brasil 2 Depart. M icrobiologia Geral, Inst. M icrobiologia-C CS, Bl. I, Universidade Federal do Rio de J aneiro, 21941, Brasil 3Universitk des Sciences et Techniques de Lille-Flandres-Artois, 59.655, France 4Unit~ 16, INSERM, Place de Verdun, Lille, France Received 26 August 1991 fl-Elimination of peptidorhamnomannans purified from yeast-like and mycelial phases of Sporothrix schenckii released neutral and acidic reduced oligosaccharides that were O linked to serine and/or threonine. Man- (~l-2)Man-ol, Rha(~l-3)Mau(al-2)Man-ol, Rha(ctl-4)GlcA(~l-2)Man(al-2)Man-ol, and Rha(~l-4)[Rha(~l-2)] GlcA(al-2)Man(al-2)Man-ol were characterized based on methylation analysis, proton magnetic resonance and fast atom bombardment mass spectrometry. Keywords: Oligosaccharides, Sporothrix sehenckii Abbreviations: FAB, fast atom bombardment; GLC, gas liquid chromatography; GlcA, D-glucopyranosyluronic acid; Man, D-mannopyranose; Man-ol, D-mannitol; MS, mass spectrometry; NMR, nuclear magnetic resonance; Rha, L-rhamnopyranose. Sporothrix schenckii is a dimorphic pathogenic fungus forming hyphae and conidia at room temperature, and yeast-like cells at 37 °C [1]. Dimorphic fungi are good models for studies of the correlation of the expression of cellular components and morphological differentiation [2-4]. With this purpose, several studies have appeared on the association of cell surface molecules and the cell shape [5], their role in immunogenic aspects [6-8] as well as in fungal penetration of host cells [9]. Previous reports showed that the polysaccharides isolated from S. schenckii contain rhamnose and mannose as the major constituents [10-12]. These sugar residues have also been found in several species of Ceratocystis [11, 12], Graphium [13] and Europium [14], and are responsible for the serological crossreactivity among these genera and S. schenckii [14]. Structural analysis of rhamnomannans isolated by alkaline extraction from S. schenckii cultures, characterized single-unit ~-L-rhamnopyranosyl side chains in the yeast-like [11-15] and conidial forms [16], whereas (1-2)-linked di-e-L-rhamnopyranosyl side chains were iden- tified in the mycelial phase [11, 15]. Both side chains are attached to positions 3 on a (1-6)-linked ~-D-mannan, and are the main antigenic determinants in such molecules [17]. However, it became clear that some reactivities of the peptidorhamnomannans with antibodies [17] and lectins [18] could involve carbohydrate structures other than the 0282-0080 © 1992Chapman & Hall N linked polysaccharide chains in the glycoconjugate. Therefore we started looking for O linked oligosaccharide chains in these molecules. In the present paper, we report experiments on the fl-elimination of purified peptidorhamnomannans isolated from different cell types of S. schenckii, and the characteriza- tion of the resulting O linked oligosaccharides. Materials and methods Microorganism and growth conditions S. schenckii strain 1099-18 was isolated from a human case of sporotrichosis and was originally obtained from the Mycology Section of the Department of Dermatology, Columbia University, New York, USA. Yeast forms of S. schenckii were obtained at 37 °C in brain heart infusion (BHI). Cultures in the mycelial phase were grown at 25 °C in Sabouraud (2% glucose, 0.5% yeast extract, 1% peptone) medium. Fresh cultures in solid Sabouraud were used as inocula. Transfers were initially made to flasks containing 200 ml BHI or Sabouraud media and incubation carried out with shaking for 3-4 days. Once a stable morphological phase was established the entire culture volume was used as inoculum for 3 1 Erlenmeyer flasks containing 11 of the same medium.