title: A thaumatin-like protein from larvae of the beetle Dendroides canadensis enhances the activity of antifreeze proteins.
abstract: The levels of thermal hysteresis (antifreeze activity) produced by purified antifreeze proteins (DAFPs) from the larvae of the beetle Dendroides canadensis at endogenous concentrations are lower than what are present in the hemolymph of overwintering larvae. Thermal hysteresis activity of DAFPs is dependent not only on AFP concentration but also on the presence of enhancers that may be either proteins (including other hemolymph DAFPs) or low-molecular mass enhancers such as glycerol. The purpose of this study was to identify endogenous protein enhancers using yeast two-hybrid, co-immunoprecipitation, and finally the enhancement of antifreeze activity. Here we show that a thaumatin-like protein from D. canadensis, until recently known only from plants, significantly enhances the thermal hysteresis of DAFP-1 and -2. Glycerol can further this enhancement, presumably by promoting the interaction of the DAFPs and thaumatin-like protein.
authors.affiliation: Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: John G
authors.initials: JG
authors.lastname: Duman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D021301:Antifreeze Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001517:Coleoptera / Q000201:enzymology / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006458:Hemolymph / Q000378:metabolism; D007814:Larva / Q000201:enzymology / Q000378:metabolism*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques
chemical_list: D021301:Antifreeze Proteins; D010940:Plant Proteins; D020033:Protein Isoforms; D011994:Recombinant Proteins; C003427:thaumatin protein, plant