MRI: An Ultra High Resolution Mass Spectrometer to Identify Novel Protein Sequences and Modifications from Extinct Organisms Such as Tyrannosaurus Rex

获得灭绝生物分子序列的能力将对评估物种进化产生巨大影响。来自灭绝生物的古代化石通常已经降解，几乎没有有机物质留下来进行分子分析。我们正在开发一种非常敏感的方法，使用质谱和生物信息学来提取和测序保存完好的骨骼中的可用蛋白质（主要是胶原蛋白）。对于6800万年前的化石，如保留软组织的霸王龙雷克斯，我们提取并测序了胶原蛋白的小片段，并获得了160，000 - 600，000年前乳齿象化石的重要序列信息。对于这样的标本，DNA是不容易获得的，蛋白质是唯一可测序的有机材料。这些序列以低分辨率获得，使得许多同量异位氨基酸和修饰的氨基酸不能被充分分辨。 该主要研究仪器（MRI）计划拨款的资金为收购ThermoScientific LTQ-Orbitrap质谱仪提供了部分支持，该质谱仪具有超高分辨率和质量精度，将为PI提供充分解析这些序列及其修改的能力，而不会产生歧义，并具有更高的灵敏度，以获取数百万年前化石的序列信息。最近发掘出许多保存完好的化石，将使用PI方法对这些化石进行测序。这些序列将用于评估它们与现代生物以及其他灭绝生物的进化关系。 该仪器将被安置在贝斯以色列女执事医疗中心，33%的仪器时间将用于地面研究。 来自北卡罗来纳州州立大学的学生在脊椎动物和分子古生物学方面进行研究，将有机会接受这种最先进技术的培训。

The ability to obtain molecular sequence for extinct organisms will have a dramatic impact on the assessment of the evolution of species. Ancient fossils from extinct organisms are usually degraded and little organic material remains for molecular analysis. We are developing a very sensitive approach using mass spectrometry and bioinformatics for extracting and sequencing available protein (mainly collagen) that remains in well-preserved bones. For fossils as old as 68 million years such as a Tyrannosaurus rex preserving soft tissues, we have extracted and sequenced small fragments of collagen as well as acquired significant sequence information for a 160,000-600,000 year old mastodon fossil. For such specimens, DNA is not readily available and protein is the only sequenceable organic material. These sequences were acquired in low resolution so that many isobaric amino acids and modified amino acids could not be sufficiently resolved. Funding from this Major Research Instrumentation (MRI) Program grant provides partial support for the acquisition of a ThermoScientific LTQ-Orbitrap mass spectrometer capable of ultra high resolution and mass accuracy that will afford the PIs the ability to sufficiently resolve these sequences and their modifications without ambiguity and with greater sensitivity to acquire sequence information on fossils that are many millions of years old. Many fossils showing excellent preservation fossils have been recently excavated and these will be sequenced using the PIs approach. These sequences will then be used to assess their evolutionary relationships with modern organisms as well as other extinct organisms. The instrument will be housed at Beth Israel Deaconess Medical Center and 33% of the instrument time will be dedicated for terrestrial research. Students from North Carolina State University conducting research in vertebrate and molecular paleontology will be afforded the opportunity for training on this state-of-the-art technology.