title: The antifreeze potential of the spruce budworm thermal hysteresis protein.
abstract: Antifreeze proteins (AFP) inhibit ice growth by surface adsorption that results in a depression of the freezing point below the melting point. The maximum level of this thermal hysteresis shown by the four structurally unrelated fish AFP is approximately 1.5 degrees C. In contrast, hemolymph and crude extracts from insects can have 5 degrees to 10 degrees C of thermal hysteresis. Based on the isolation, cloning, and expression of a thermal hysteresis protein (THP) from spruce budworm (Choristoneura fumiferana), the vastly greater activity is attributable to a 9 kDa protein. This novel, threonine- and cysteine-rich THP has striking effects on ice crystal morphology, both before and during freezing. It is also 10 to 30 times more active than any known fish AFP, offering the prospect of superior antifreeze properties in cryoprotective applications.
authors.affiliation: Department of Biology, Queen's University, Kingston, Ontario, Canada.
authors.forename: M G
authors.initials: MG
authors.lastname: Tyshenko
authors.forename: D
authors.initials: D
authors.lastname: Doucet
authors.forename: P L
authors.initials: PL
authors.lastname: Davies
authors.forename: V K
authors.initials: VK
authors.lastname: Walker
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D021301:Antifreeze Proteins; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D019143:Evolution, Molecular; D005615:Freezing; D006023:Glycoproteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification*; D007053:Ice; D007814:Larva; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009036:Moths / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics; D013499:Surface Properties
chemical_list: D021301:Antifreeze Proteins; D018076:DNA, Complementary; D006023:Glycoproteins; D007053:Ice; D011994:Recombinant Proteins