title: Hpf2 glycan structure is critical for protection against protein haze formation in white wine.
abstract: Grape-derived proteins can form haze in wine. Some cell-wall glycoproteins of Saccharomyces cerevisiae are capable of reducing protein haze formation. The basis of their haze protective activity is not yet understood. One of the S. cerevisiae cell-wall proteins, Hpf2, was produced in Pichia pastoris . An altered glycan structure in the P. pastoris -produced protein was associated with decreased solubility in water and reduced capacity to mitigate haze formation compared to native Hpf2 protein from S. cerevisiae. alpha-1,2-Linked mannose in the glycan chain was shown to be required for haze protective activity using a series of S. cerevisiae deletion mutants (mnn1-Delta, mnn2-Delta, mnn4-Delta, and mnn5-Delta), defective in different aspects of glycan processing. The effect of media additives phthalate, casamino acids, and yeast nitrogen base on Hpf2 production in P. pastoris were also evaluated. Casamino acids were shown to suppress Hpf2 production in P. pastoris .
authors.affiliation: The Australian Wine Research Institute, Glen Osmond 5064, South Australia, Australia. simon.schmidt@awri.com.au
authors.forename: Simon A
authors.initials: SA
authors.lastname: Schmidt
authors.forename: Ee Leng
authors.initials: EL
authors.lastname: Tan
authors.forename: Shauna
authors.initials: S
authors.lastname: Brown
authors.forename: Uli J
authors.initials: UJ
authors.lastname: Nasution
authors.forename: Filomena
authors.initials: F
authors.lastname: Pettolino
authors.forename: Oenone J
authors.initials: OJ
authors.lastname: Macintyre
authors.forename: Miguel de Barros
authors.initials: Mde B
authors.lastname: Lopes
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Waters
authors.forename: Peter A
authors.initials: PA
authors.lastname: Anderson
mesh_terms: D002473:Cell Wall / Q000737:chemistry*; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics; D005822:Genetic Vectors; D006031:Glycosylation; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000235:genetics; D009154:Mutation; D010843:Pichia / Q000378:metabolism; D011134:Polysaccharides / Q000737:chemistry*; D011994:Recombinant Proteins / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000737:chemistry* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics; D013329:Structure-Activity Relationship; D014920:Wine / Q000032:analysis*
chemical_list: D005656:Fungal Proteins; C542053:Hpf2 protein, S cerevisiae; D008562:Membrane Glycoproteins; D011134:Polysaccharides; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins