Effects of polyhydroxy compounds on beetle antifreeze protein activity

• Published in: Biochimica et biophysica acta 2009-02, Vol.1794 (2), p.341-346
• Main Authors: Amornwittawat, Natapol, Wang, Sen, Banatlao, Joseph, Chung, Melody, Velasco, Efrain, Duman, John G., Wen, Xin
• Format: Article
• Language: English
• Subjects: Animals; Antifreeze protein; Antifreeze protein activity enhancement; Antifreeze Proteins - chemistry; Calorimetry, Differential Scanning; Carbohydrates - chemistry; Coleoptera - metabolism; Dendroides canadensis; Differential scanning calorimetry; Phenols - chemistry; Polyhydroxy compounds; Protein Isoforms - chemistry; Structure-Activity Relationship; Thermal hysteresis activity; Trehalose - chemistry
• ISSN: 1570-9639; 0006-3002; 1878-1454
• DOI: 10.1016/j.bbapap.2008.10.011

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.