IDENTIFICATION AND MOLECULAR BASIS FOR EFFICIENT ANTIFREEZE PROTIEN ENHANCERS

描述(由申请人提供)：抗冻蛋白(AFP)已在许多生物体中被鉴定，如鱼、植物和昆虫，使它们能够在零度以下的温度下生存。它们的特点都是能够在不明显改变熔点的情况下降低溶液的冰点，从而产生热滞。昆虫AFP通常是最活跃的AFP(比I型鱼类AFP的活性高10-100倍)。在某些共溶质(称为促进剂)的存在下，许多AFP的抗冻活性可以进一步增强。小分子化学物质和大分子物质都被认为是AFP的促进剂，其中一些促进剂确实在生理上起到了增强AFP抗冻活性的作用。据报道，一些增强剂可以与AFP特异性结合。然而，这种增强效应的机制仍未得到很好的描述。加拿大金龟子甲胎蛋白(DAFP)及其促进剂已被广泛研究。增强剂与AFP的结合是增强剂增强AFP抗冻活性的重要机制之一。不同的AFP系统中的增强现象是否有共同的机制？在这个项目中，我们将研究一个重要的甲虫AFP系统，来自黄粉虫的粉虫AFP(TmAFP)及其增强子。我们认为，增强剂对TmAFP抗冻活性的增强效果取决于增强剂的物理化学性质。我们将评估选定的胺衍生物对TmAFP抗冻剂活性的增强效率，并将它们的增强效率与它们不同的物理化学性质相关联。我们将确定TmAFP与增强剂之间可能的相互作用，并确定TmAFP中与增强剂结合的关键氨基酸。对AFP和增强剂的研究对于增进我们对生物系统的理解和促进开发高效的AFP系统以用于其实际生物医学应用是至关重要的，例如在实验室和人类健康中的低温保存组织以及其他工业应用，如在冷冻食品和水合物抑制中。这项拟议的研究将为AFP和AFP增强剂的分子机制提供深入的见解，并解决关于AFP作用机制的相互矛盾的报道。

DESCRIPTION (provided by applicant): Antifreeze proteins (AFPs) have been identified in a number of organisms, such as fish, plants, and insects, to allow them to survive at subfreezing temperatures. They are all characterized by their ability to depress the freezing point of the solution without appreciably altering the melting point thereby producing a thermal hysteresis. Insect AFPs are often the most active AFPs (10-100 times more active than type I fish AFPs). The antifreeze activities of many AFPs can be further enhanced in the presence of certain co-solutes (called enhancers). Both low molecular mass chemicals and macromolecules have been identified as enhancers for AFPs and some of the enhancers do play a role in enhancing the antifreeze activity of AFPs physiologically. Some of the enhancers have been reported to bind AFPs specifically. The mechanism of the enhancement effect, however, is still poorly described. The AFP from the beetle Dendroides canadensis (DAFP) and the enhancers have been extensively studied. The binding of enhancers to AFP has been demonstrated as one important mechanism for the enhancement effect of enhancers on the antifreeze activity of AFPs. Is there a common mechanism for the enhancement phenomena in different AFP systems? In this project, we will examine an important beetle AFP system, a mealworm AFP from Tenebrio molitor (TmAFP) and the enhancers. We propose that the enhancement efficiency of the enhancers for TmAFP antifreeze activity depends on the physiochemical properties of the enhancers. We will assess the enhancement efficiency of selected amine derivatives on TmAFP antifreeze activity and correlate their enhancement efficiency with their differing physicochemical properties. We will identify the possible interactions between TmAFP and the enhancers and determine the key amino acids in TmAFP involving in binding to the enhancers. The study of AFPs and enhancers is essential to advance our understanding of the biological system and facilitate the development of highly efficient AFP systems for their practical biomedical applications, such as in preservation of tissues at low temperatures in the lab and in human health as well as other industrial applications, such as in frozen foods and in hydrate inhibition. The proposed research will provide insights into the molecular mechanism of AFP and AFP enhancers and resolve conflicting reports regarding the mechanism of action of AFPs.