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A mannose‐binding protein from the cell surface of flocculent Saccharomyces cerevisiae (NCIM 3528): its role in flocculation
Author(s) -
Javadekar V. S.,
Sivaraman H.,
Sainkar S. R.,
Khan M. I.
Publication year - 2000
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/(sici)1097-0061(20000130)16:2<99::aid-yea500>3.0.co;2-6
Subject(s) - lectin , mannose , biology , biochemistry , yeast , saccharomyces cerevisiae , mannan binding lectin , peptide sequence , flocculation , affinity chromatography , teichoic acid , concanavalin a , microbiology and biotechnology , amino acid , cell wall , gene , chemistry , in vitro , enzyme , organic chemistry , peptidoglycan
A cell surface lectin was isolated and purified to homogeneity from the cell walls of a highly flocculent strain of Saccharomyces cerevisiae (NCIM 3528) by chromatography on DEAE‐cellulose, phenyl Sepharose and Sephacryl S‐300. It showed a molecular mass of 40 kDa on SDS–PAGE. It is an acidic protein with a pI of 4.0 and contains 44% hydrophobic amino acids. The N‐terminal sequence up to 10 amino acid residues showed at least 70% homology with the predicted N‐terminal sequence of the putative FLO1 as well as FLO5 gene products. The mannose‐binding nature of the lectin was indicated by its high affinity and specificity towards the branched trisaccharide of mannose, a ligand which also inhibits the flocculation of yeast cells. Immunofluorescence studies confirmed the presence of lectin on the yeast cell surface and lectin‐specific IgGs prevented flocculation of the cells. This cell surface mannose‐specific lectin probably plays an important role in flocculation, with the branched trimannoside on the cell wall being the apparent carbohydrate receptor. The N‐terminal sequence data gives a primary indication that the lectin could be a product of one of the FLO genes. Copyright © 2000 John Wiley & Sons, Ltd.