An antigenic water-soluble glucogalactomannan extracted from cell walls of Paecilomyces fumosoroseus and Paecilomyces farinosus

Abstract

The water-soluble fraction (FlS) obtained after solubilizing in alkali the cell walls of four strains of Paecilornyces furnosoroseus and two of Paecilornyces farinosus amounted to 83-14*5% of the dry cell wall material. Two polysaccharides, F1 S-A (1 3-20 YO) and F1 S-B (57-68 YO) were separated from F1 S by gel permeation through Sepharose CL-6B. lH and 13C NMR spectra of F1S-B were recorded and showed analogous structural features in the six isolates of the two species. The fractions isolated from P. furnosoroseus strain CBS 375.70were subjected to structural analysis and shown to be a (1 -, 4)-a=glucan (FlS-A) and a branched (1 + 6)lmannan with terminal residues of pgalactopyranose (F1 S-B). Polyclonal antibodies against the latter polysaccharide were obtained (titre 1/8000). These antibodies reacted specifically with the F1S-B polysaccharides obtained from the four strains of P. furnosoroseus and the two strains of P. farinosus, but they did not react with similar fractions from other species of the same or related genera. The antibodies specifically stained P. furnosoroseus hyphae in indirect immunof luorescence tests.

Structures of wall heterogalactomannans isolated from three genera of entomopathogenic fungi

“…In these two cases, it was demonstrated that the surface galactomannan from the mycopathogen is recognized and binds to specific lectins in the hosts, as an initial step previous to the secretion of the hydrolytic enzymes that lead to the development of the disease (Bernardo et al 2004;Bernardo et al 2005). Entomopathogenic species like Paecilomyces farinosus and Paecilomyces fumosoroseus (now Isaria farinosa and Isaria fumosorosea, respectively) have also galactomannans with similar structures (Domenech et al 1996). All these data reinforce the idea that the surface wall galactomannans of plant, fungal and insect pathogens can play a role in the infectivity against their hosts.…”

“…They have been proposed as chemotaxonomic and evolutionary characters for the ascomycetes because of the wide variety of structures found in different fungal groups (Leal et al 2010). These polysaccharides are located in the surface of the fungal hyphae, where they can establish a close contact with the external environment (Domenech et al 1996;Ahrazem et al 2000). It has been shown that adhesion of fungal parasites to the host cell surface probably involves binding of these surface polysaccharides to complementary host molecules (Pendland & Boucias 1993;Bernardo et al 2004).…”

Chemical components and their locations in the Verticillium fungicola cell wall

“…The preparations were washed 3 times with 2 mL PBS for 5 min, and saturated with 3% (w/v) BSA diluted in PBS for 30 min. The samples were incubated for 1 h at 37°C with 20 µL of the antiserum (diluted 1/200 in 3% BSA in PBS) against water-soluble glucogalactomannan of Paecilomyces fumosoroseus cell walls obtained by Domenech et al (1996). After washing twice with PBS and gentle agitation (5 min), the coverslips were overlaid with 20 µL goat anti-rabbit rhodamine conjugate (Sigma), diluted 1/100 in 3% BSA in PBS, incubated for 45 min at 37°C, washed with PBS in the dark, and mounted with 0.13 M glycine buffer pH 8.6, 0.2 M NaCl, 70% (v/v) glycerol.…”

Comparative studies of the polysaccharides isolated from lichenized fungi of the genus Cladonia: significance as chemotypes

“…In this case, wall polysaccharides were useful tools in the classi¢cation and identi¢cation of yeasts [25] and other fungi [26,27,28]. In the latter, studies were performed using polysaccharides to originate antibodies that can be used to distinguish related species [29].…”