Solubilizationandcharacterizationofa cell wall-boundtrehalasefromascosporesofthe fission yeast Schizosaccharomycespombe

摘要

The genomeofthefissionyeast Schizosaccharomyces pombe lacks sequence homologs to ath1 genes codingforacidtrehalasesinotheryeastsorfilamentous fungi. However,acidtrehalaseactivityispresentatthesporestageinthelifecycle of thefissionyeast.Theenzymeresponsibleforthisactivitybehavesasasurface enzyme covalentlylinkedtothesporecellwallsinbothwild-typeand ntp1 mutant strains devoidofneutraltrehalase.Lytictreatmentofparticulatedcellwall fractions allowedthesolubilizationoftheenzymeintoanactiveform.Wehave characterized thissolubleenzymeandfoundthatitskineticparameters,optimum pH andtemperature, thermaldenaturationandsaltresponsesarecloselysimilarto other conventionalacidtrehalases.Hence,thisratherunusualenzymecanbe recognized asacidtrehalasebyitsbiochemicalpropertiesalthoughitdoesnotshare genetic homologywithotherknownacidtrehalases.Thepotentialroleofsuchacid trehalase inthemobilizationoftrehaloseisdiscussed. & 2007 ElsevierGmbH.Allrightsreserved.