IDENTIFICATION AND MOLECULAR BASIS FOR EFFICIENT ANTIFREEZE PROTEIN ENHANCERS

 说明(申请人提供)：抗冻蛋白(AFP)是一种天然的抗冻分子，存在于许多生物中，包括鱼、昆虫、植物、细菌和真菌。AFPS表现出很大的结构多样性，但它们都具有独特的能力，可以在不明显影响熔点的情况下降低水的凝固点。由此产生的熔点和冰点之间的差异，称为热滞(TH)，通常被用来衡量AFP的防冻活性。冷适应生物体液中的黄曲霉毒素和共溶质是在寒冷环境中生存的主要因素。某些小分子和大分子共溶质可以进一步增强AFP的抗冻活性，被称为增强剂，它们通常没有TH活性，但可以通过离子相互作用、氢键和/或疏水作用与AFP结合。基于甲胎蛋白的防冻剂系统(甲胎蛋白加增强剂)比传统防冻剂更有效，其用途更环保，使其成为传统防冻剂的有趣替代品，特别是在生物医学领域。拟议的研究将使用一系列甲虫甲胎蛋白-小分子增强剂系统，其中小分子增强剂显示出广泛的防冻增强能力。我们将在这些系统中使用化学和生物物理方法来确定AFP与增强子之间的结合特性，并揭示高效AFP系统中AFP与增强子的亲和力。我们还将确定影响AFP-增强子系统结合的因素。盐的影响将被确定。我们将在拟议的AFP-增强子系统的功能检查中优化这些因素。定量了解基于AFP的防冻体系将有助于揭示冷适应生物的生存策略，并有助于合理开发高效的冷保存、用于实际生物医学应用的防冻体系，如在器官、组织和细胞移植、冷冻保存和冷冻外科的保存液中。

 DESCRIPTION (provided by applicant): 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 macromolecule co-solutes can further enhance the antifreeze activity of AFPs, referred to as enhancers, and they usually do not have TH activity, but can bind 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 use series of beetle AFP-small molecule enhancer systems, in which small molecule enhancers display a wide range of antifreeze enhancement abilities. We will determine the binding characteristics between AFPs and enhancers using chemical and biophysical approaches in these systems and unravel the AFP-enhancer affinity in highly efficient AFP systems. We will also determine the factors that can affect the binding in the AFP-enhancers systems. The salt effects will be determined. We will optimize these factors in the proposed functional examinations of the AFP-enhancer systems. Quantitative understanding AFP-based antifreeze systems would help unravel survival strategy in cold-adapted organisms and lead to rational development of highly efficient cold preservation, antifreeze systems for practical biomedical applications, such as in preservation solutions for organ, tissue and cell transplantation, cryopreservation, and cryosurgery.