Protein Aggregation in Amorphous Solids

描述（由申请人提供）：蛋白质药物是制药工业中增长最快的部分之一。对这些药物的强劲需求反映了它们治疗以前难治性疾病的能力，包括癌症、传染病、自身免疫性疾病和心血管疾病。目前市场上超过40%的蛋白质药物产品是无定形固体，通常选择这种形式是为了延长保质期和保持效力。然而，蛋白质药物在固体状态下经历了多种物理和化学降解过程。聚合是这些过程中最常见的一种。由于聚集体的存在与效力降低和危及生命的免疫原性副作用的可能性增加有关，因此必须在生产和储存期间检测和清除聚集体。这增加了生产蛋白质药物的成本，最终增加了患者的成本，并阻碍了无法有效稳定的有希望的新蛋白质药物的商业化。本研究计划的目标是在全面了解所涉及的化学（即共价）和物理（即非共价）机制的基础上，开发合理的方法来防止蛋白质在固态中聚集。核心假设是，蛋白质在无定形固体中的聚集是特定共价反应和/或暴露于蛋白质序列中易于聚集的“热点”的结果，这两种情况都可以通过设计固体环境来防止。为Specific Aim 1提出的研究将阐明硫醇-二硫化物交换和二硫化物在非晶固体中的置乱机制，并将确定控制这些反应的固体性质。这些研究验证了一个假设，即这些共同的共价聚集途径在溶液和固体状态下有利于不同的途径，并受到固体组成的影响。Specific Aim 2将利用氢/氘（H/D）交换和分子动力学模拟（MDS）识别非共价蛋白在非晶态固体中聚集的“热点”。这项工作验证了一个假设，即这些定量的、高分辨率的非晶态固体中蛋白质结构的测量将与长期储存过程中的非共价聚集有关。Specific Aim 3将开发一个计算模型，根据蛋白质和固体的性质预测蛋白质在非晶态固体中的聚集，为配方设计和识别防止聚集的关键变量提供工具。这项工作与NIH的使命有关，即提高国家保护和改善健康的能力，因为它解决了保持快速增长的一类药物的效力和安全性的方法。这项工作也符合该机构的目标，即通过为将活性蛋白开发成可销售的药物产品提供工具和知识，确保公共研究投资的持续高回报。蛋白质药物产品中聚集物的存在增加了患者用药时发生危及生命的免疫原性反应的可能性。了解非晶固体中的聚集体形成将有助于确保这种快速增长的药物类别的安全性。该工作还将有助于控制药物开发成本，为蛋白质药物配方提供合理依据。

DESCRIPTION (provided by applicant): Protein drugs are one of the fastest growing segments of the pharmaceutical industry. The strong demand for these drugs reflects their ability to treat previously intractable diseases, including cancers, infectious disease, autoimmune disorders and cardiovascular disease. More than 40% of currently marketed protein drug products are amorphous solids, a form often chosen to prolong shelf-life and preserve potency. Nevertheless, protein drugs undergo a variety of physical and chemical degradation processes in the solid state. Aggregation is one of the most common of these processes. Since the presence of aggregates is associated with decreased potency and with an increased potential for life-threatening immunogenic side effects, they must be detected and removed during manufacturing and storage. This adds to the cost of producing protein drugs, ultimately increasing the cost to the patient and precluding the commercialization of promising new protein drugs that cannot be stabilized effectively. The goal of this research program is to develop rational methods for preventing protein aggregation in the solid state based on a thorough understanding of the chemical (i.e., covalent) and physical (i.e., non- covalent) mechanisms involved. The central hypothesis is that protein aggregation in amorphous solids is the result of specific covalent reactions and/or the exposure of aggregation-prone "hot spots" in the protein sequence, both of which can be prevented by designing the solid environment. Studies proposed for Specific Aim 1 will elucidate the mechanisms of thiol-disulfide exchange and disulfide scrambling in amorphous solids and will identify solid properties that control these reactions. The studies test the hypothesis that these common routes of covalent aggregation favor different pathways in solution and in the solid state and are influenced by solid composition. Specific Aim 2 will identify "hot spots" for non-covalent protein aggregation in amorphous solids using hydrogen/deuterium (H/D) exchange and molecular dynamics simulation (MDS). The work tests the hypothesis that these quantitative, high resolution measures of protein structure in amorphous solids will correlate with non-covalent aggregation during long-term storage. Specific Aim 3 will develop a computational model that predicts protein aggregation in amorphous solids based on properties of the protein and solid, producing a tool for formulation design and identifying variables critical to preventing aggregation. The work is relevant to the NIH mission of advancing the Nation's capacity to protect and improve health in that it addresses methods to preserve the potency and safety of a rapidly growing class of drugs. The work is also consistent with the agency's goal of ensuring a continued high return on the public investment in research by providing tools and knowledge for developing active proteins into marketable drug products. The presence of aggregates in protein drug products increases the potential for life-threatening immunogenic responses when the drugs are administered to patients. Understanding aggregate formation in amorphous solids will help ensure the safety of this rapidly growing drug class. The work will also help to control drug development costs by providing a rational basis for protein drug formulation.