Rk. Li et Je. Cutler, CHEMICAL DEFINITION OF AN EPITOPE ADHESIN MOLECULE ON CANDIDA-ALBICANS, The Journal of biological chemistry, 268(24), 1993, pp. 18293-18299
An antigen (Ag), as defined by reactivity with a monoclonal antibody (
mAb 10G), was found on the cell wall surface and on the plasma membran
e of Candida albicans yeast cells (Li, R. K., and Cutler, J. E. (1991)
J. Gen. Microbiol. 137, 455-464). The 10G Ag from the cell surface lo
cation was solubilized by treatment with beta-mercaptoethanol and Zymo
lyase. Antigenic activity of the extract was lost following periodate
oxidation, but was stable to proteolytic enzyme and heat treatments. M
annoproteins in the extract were fractionated by hexadecyltrimethylamm
onium bromide. A fraction containing the 10G Ag was degraded by mild a
cid hydrolysis and a tetrahexose eluted from a P-2 size exclusion colu
mn was found to be the epitope (10G epitope) part of the 10G Ag. By us
e of gas-liquid chromatography, mass spectroscopy, and H-1 proton NMR
analysis, the 10G epitope was determined to be a linear beta-1,2-linke
d tetramannose. The 10G Ag, which was immunopurified from the Zymolyas
e extract, and the 10G epitope were involved in the attachment of C. a
lbicans to mouse spleen marginal zone macrophages. Both the 10G Ag and
the purified 10G epitope specifically inhibited C. albicans adherence
in an ex vivo binding assay. Latex beads adsorbed with the 10G Ag or
the 10G epitope adhered specifically to the splenic marginal zone macr
ophages. These data show that a beta-1,2-linked mannotetraose part of
a C. albicans cell wall mannoprotein is an adhesin site that may play
a role in pathogenesis of disseminated candidiasis.