IDENTIFICATION AND MOLECULAR BASIS FOR EFFICIENT ANTIFREEZE PROTEIN ENHANCERS

摘要/概要 抗冻蛋白（Antifreeze Proteins，AFPs）是一种存在于多种生物体内的天然抗冻分子 包括鱼类、昆虫、植物、细菌和真菌。AFP具有很大的结构多样性，而它们都是 其特征在于它们独特的降低水的凝固点而不影响熔点的能力 显然是的由此产生的熔点和凝固点之间的差异，称为热 滞后（TH）通常用作AFP抗冻活性的量度。AFP和共溶质 冷适应生物体的体液负责在冷环境中的存活。某些小 分子和蛋白质共溶质可以进一步增强AFP的抗冻活性，称为增强剂， 通过离子相互作用、氢键和/或疏水相互作用与AFP结合。基于AFP 防冻系统（AFP加增强剂）更有效，其用途更环保 与传统防冻剂相比，它们是友好的，使它们成为传统防冻剂的有趣替代品。 防冻剂，特别是在生物医学领域。这项拟议中的研究将调查鲜为人知的AFP- 蛋白质系统通过确定AFP对其他蛋白质的冷冻保护作用以及 这些蛋白质的抗冻活性的AFP使用组合的生物化学和生物物理方法。 关于AFP-蛋白质系统中这种相互作用的信息不仅将进一步加深我们对AFP-蛋白质系统的理解， 生物抗冻系统在冷适应生物，而且还导致发展有效的保护 生物医学应用中重要生物制品的长期保存系统。

Abstract/Summary Antifreeze proteins (AFPs) are natural antifreeze molecules that have been found in many organisms including fish, insects, plants, bacteria, and fungi. AFPs exhibit great structural diversity, while they are all characterized by their unique ability to depress the freezing point of water without affecting the melting point apparently. The resulting difference between the melting point and the freezing point, referred to as thermal hysteresis (TH), is generally used as a measure of the antifreeze activities of AFPs. AFPs and co-solutes in body-fluids of cold-adapted organisms are responsible for survival in cold environments. Certain small molecule and protein co-solutes can further enhance the antifreeze activity of AFPs, referred to as enhancers, by binding to AFP through ionic interactions, hydrogen bonding, and/or hydrophobic interactions. AFP-based antifreeze systems (AFP plus enhancer) are much more effective and their uses are more environmentally friendly in comparison to conventional antifreezes, making them intriguing alternatives to conventional antifreezes in particular in biomedical fields. The proposed research will investigate the little known AFP- protein systems through determining the cryoprotective effect of an AFP on other proteins as well as the effect of these proteins on the antifreeze activity of the AFP using combined biochemical and biophysical methods. The information on such interplay in the AFP-protein systems would not only further our understanding of biological antifreeze system in cold-adapted organisms, but also lead to the development of effective protective systems for long-term preservation of important biologics in biomedical applications.