title: Purification and partial characterization of a flocculin from brewer's yeast.
abstract: Analysis of a shear supernatant from flocculent, "fimbriated" Saccharomyces cerevisiae brewer's yeast cells revealed the presence of a protein involved in flocculation of the yeast cells and therefore designated a flocculin. The molecular mass of the flocculin was estimated to be over 300 kDa, as judged from sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Gel permeation chromatography of the flocculin yielded an aggregate with an apparent molecular weight of > 2,000. The flocculin was found to be protease sensitive, and the sequence of its 16 N-terminal amino acids revealed at least 69% identity with the predicted N terminus of the putative protein encoded by the flocculation gene FLO1. The flocculin was isolated from flocculent S. cerevisiae cells, whereas only a low amount of flocculin, if any, could be isolated from nonflocculent cells. The flocculin was found to stimulate the flocculation ability of flocculent yeast cells without displaying lectinlike activity (that is, the ability to agglutinate yeast cells).
authors.affiliation: Institute of Molecular Plant Sciences, Leiden University, The Netherlands.
authors.forename: M H
authors.initials: MH
authors.lastname: Straver
authors.forename: G
authors.initials: G
authors.lastname: Smit
authors.forename: J W
authors.initials: JW
authors.lastname: Kijne
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D005427:Flocculation; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D037241:Mannose-Binding Lectins; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D029701:Saccharomyces cerevisiae Proteins; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid
chemical_list: D000596:Amino Acids; C087578:FLO1 protein, S cerevisiae; D005656:Fungal Proteins; D037241:Mannose-Binding Lectins; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins