Effects of polyhydroxy compounds on beetle antifreeze protein activity.
Antifreeze proteins (AFPs) noncolligatively depress the nonequilibrium freezing point of a solution and produce a difference between the melting and freezing points termed thermal hysteresis (TH). Some low-molecular-mass solutes can affect the TH values. The TH enhancement effects of selected polyhydroxy compounds including polyols and carbohydrates on an AFP from the beetle Dendroides canadensis were systematically investigated using differential scanning calorimetry (DSC). The number of hydroxyl groups dominates the molar enhancement effectiveness of polyhydroxy compounds having one to five hydroxyl groups. However, the above rule does not apply for polyhydroxy compounds having more than five hydroxyl groups. The most efficient polyhydroxy enhancer identified is trehalose. In a combination of enhancers the strongest enhancer plays the major role in determining the TH enhancement. Mechanistic insights into identification of highly efficient AFP enhancers are discussed.
Amornwittawat
Natapol
N
Department of Chemistry and Biochemistry, California State University Los Angeles, Los Angeles, CA 90032, USA.
Wang
Sen
S
Banatlao
Joseph
J
Chung
Melody
M
Velasco
Efrain
E
Duman
John G
JG
Wen
Xin
X
D000818:Animals; D021301:Antifreeze Proteins / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002241:Carbohydrates / Q000737:chemistry*; D001517:Coleoptera / Q000378:metabolism*; D010636:Phenols / Q000737:chemistry*; D020033:Protein Isoforms / Q000737:chemistry; D013329:Structure-Activity Relationship; D014199:Trehalose / Q000737:chemistry
D021301:Antifreeze Proteins; D002241:Carbohydrates; D010636:Phenols; D020033:Protein Isoforms; D014199:Trehalose