NMR Studies of Type I Antifreeze Protein HPLC6 Function

I 型抗冻蛋白 HPLC6 功能的 NMR 研究

• 批准号: 7255719
• 负责人: YONG BA
• 金额: $ 15.17万
• 依托单位: CALIFORNIA STATE UNIVERSITY LOS ANGELES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7255719
• 关键词: binding sites; chemical kinetics; cryoprotective agents; cryoscience; dipole moment; glycoproteins; intermolecular interaction; molecular dynamics; nuclear magnetic resonance spectroscopy; protein structure function; surface property

Antifreeze proteins (AFPs) afford protection of freezing damage for organisms due to their ability to inhibit the growth and recrystallization of ice crystals. In biomedical research, AFPs found applications in cold protection of mammalian cells, tissues, and organs, and in enhancement of tumor cell destruction during cryosurgery. However, the antifreeze mechanism of AFPs remains unclear. One problem arose from the absemce of molecular-level detection techniques that can directly detect the interaction and dynamics of AFPs with and within, respectively, ice-water interfaces. In this proposed research, state of the art solid-state NMR techniques will be applied to study the antifreeze mechanism of the HPLC6 isoform of type I AFPs. The NMR techniques use local dipolar couplings of nuclear spins. Therefore, close insight into molecular-level recognition, interaction and dynamics of AFPs can be obtained. The long-term goal of this research is to provide a foundation, base on the mechanistic study, for finding more effective antifreeze materials for biomedical research and applications. Besides the significance in the field of antifreeze proteins, this research will also have broad impact on biomedical research of protein- protein, protein-membrane and protein-drug interactions in terms of development and application of NMR techniques for these studies. Four studies will be carded out to reveal the different aspects of antifreeze mechanism: (1) Reversibility and kinetics of ice-surface adsorption of HPLC6 peptides studied by Multiple Quantum Filtering-Spin Exchange and protein diffusion NMR experiments; (2) Cooperativity of HPLC6 peptides binding to ice surfaces studied by 1H and t3C Multiple Quantum NMR experiments; (3) Influence of AFPs on the kinetics and diffusion of ice-water molecules during the recrystallization process of ice studied by Quadrupolar Echo Double Resonance NMR experiment; and (4) Binding residues and surfaces ofHPLC6 peptides to ice surfaces determined by Spin Echo Double Resonance, and Rotational Echo-Adiabatic Passage-Double Resonance NMR experiments.

抗冻蛋白（AFPs）由于其抑制冰晶生长和再结晶的能力，为生物体提供了冻害保护。在生物医学研究中，AFPs被应用于哺乳动物细胞、组织和器官的低温保护，以及在冷冻手术中增强肿瘤细胞的破坏。然而，AFPs的抗冻机制尚不清楚。一个问题来自于缺乏分子水平的检测技术，这些技术可以直接检测afp与冰-水界面的相互作用和动力学。在本文提出的研究中，采用了最先进的固态