Resource for the Development of Biomedical Accelerator Mass Spectrometry (AMS)

描述（由申请人提供）：自1999年成立以来，美国国立卫生研究院资助的加速器质谱（AMS）生物医学应用研究资源在许多领域进行了许多开创性的研究，包括生物分子转换，内源性化合物和外源化合物的定量代谢，以及潜在致突变加合物的分析。AMS的高灵敏度、准确性和精密度使这些研究成为可能。本研究与发展核心提出的工作将建立在这一成功的、高影响力的研究遗产的基础上，并将扩展当前AMS实验和分析方法的适用性，以应对更广泛的科学和技术挑战。该核心的重点是蛋白质和其他生物大分子绝对定量方法的开发和常规实施。该核心将支持几个驱动生物医学项目，包括：1)表征由于人为大气14C释放而标记的组织和细胞类型的周转率（炸弹脉冲生物学）；2)蛋白质翻译后修饰的绝对定量；3)基于14c配体结合的受体鉴定；4)开发标记策略、分离技术和分析程序，用于生物基质中计算设计的合成蛋白质药物的定量，以支持动物给药实验和人体微给药研究。

DESCRIPTION (provided by applicant): Since its inception in 1999, the NIH-funded Research Resource on the biomedical applications of accelerator mass spectrometry (AMS) has performed numerous groundbreaking studies in many areas including biomolecule turnover, quantitative metabolism of endogenous compounds and xenobiotics, and analysis of potentially mutagenic adducts. These studies were made possible by the high sensitivity, accuracy, and precision of AMS. The work proposed in this TR&D core will build on this legacy of successful, high impact research and will extend the applicability of current AMS experimental and analytical methods to a wider set of scientific and technical challenges. The focus for this core i the development and routine implementation of methods for absolute quantitation of proteins and other biological macromolecules. This core will support several driving biomedical projects, including: 1) Characterization of turnover rates of tissues and cell types labeled as a result of anthropogenic atmospheric 14C release (bomb-pulse biology); 2) Absolute quantitation of protein post-translational modifications; 3) Identification of receptors based on 14C-ligand binding; and 4) Development of labeling strategies, separation techniques, and analytical procedures for quantitation of computationally-designed synthetic protein drugs in biological matrices, in support of animal dosing experiments and human microdosing studies. Biological macromolecules play a wide variety of essential roles in cells, tissues, and organisms. Proteins are the basic building blocks of all living organisms, and proteinaceous enzymes catalyze the chemical reactions responsible for life. Nucleic acids provide the genetic material containing information for building, maintaining, and regulating living organisms. Because biological macromolecules play such essential and diverse roles, improvements in our ability to quantitatively trace macromolecules and their modifications will enable important discoveries that will significantly advance our understanding of biological processes. In a recent paper, Hanke et al (Hanke et al., 2008) wrote: "Ultimately, it would be highly desirable to obtain exact quantitative values of each protein in a system, e.g., their copy number per cell or their concentration in nanogram per milliliter of body fluid. While this kind of basic information about a protein is already per se valuable for the biologist, systems biology even requires it as input for modeling. In a medical context, knowing the exact amounts of certain proteins in blood or other common sources of biomarkers can provide diagnostically relevant information for patient treatment." Analytical measurement of proteins and other biological macromolecules presents a number of significant technical challenges, particularly when quantitation is required. Macromolecule extraction from biological matrices is typically more complex than the extraction of small molecules, and extracts are more prone to contamination and degradation. Macromolecules such as proteins and nucleic acids are heterogeneous molecules, and may be chemically modified as a result of enzyme-mediated reactions (e.g., post-translational modifications) or as a result of tissue processing, as in the case of formalin-fixed tissue. In addition, biological macromolecules may be susceptible to cleavage by physical or chemical means. While analytical standards can usually be purchased or synthesized for small molecules of interest, similar standards are rarely available for biological macromolecules. The ability to measure absolute quantities of biological macromolecules has broad relevance for biology and medicine, as there currently is no standardized, universal analytical method capable of making these measurements. The major focus of this core is to develop methods for applying AMS technology, especially in conjunction with the new liquid sample AMS interface, to overcome these major challenges of biological macromolecule analysis. To this end, we propose to interact with collaborating researchers to solve a variety of important biological problems.