SGER: COLLABORATIVE RESEARCH: Biogeochemistry of Individual Proteins of Ancient and Modern Gastropods: A Molecular Level Approach to the Study of Diagenesis

从化石中分离出来的有机物质 用于确定古生态和分类基质 基于同位素和氨基酸数据的关系。 本 评价印度的标准集中在大量的有机 从化石中提取的部分，包括氨基酸分析 丰度和对映体以及13 C和15 N的比较 化石材料的价值与现代生物的价值相比。 这些标准包括两个假设，1）散装有机 材料是均匀的，2）氨基的相对丰度 酸和同位素组成与现代的 analog. 这些假设的困难在于， 材料不是均匀的，而是由几个 不同的蛋白质和化石的有机基质可能 改变了如果从化石中获得的成岩产物是 特定蛋白质的差异损失或保留的结果 地球化学特征及解释 的数据完全是蛋白质组成的函数， 有机基质。 因此，更精确和新的方法， 需要评估成岩作用的影响， 印第安人 更好地了解有机体的变化 随着时间的推移，化石材料的部分必须包括1）评估 每种蛋白质的相对贡献的变化 随着时间的推移，2）对变化的理解， 发生在单个蛋白质的生化特征中 3）新的分子水平方法， 例如评价单个氨基酸对映体的13 C (see解释的合理性）。 我们预计 拟议的研究将提供有关成岩作用的独特信息 通过对单个蛋白质的分子水平分析。

Organic material isolated from fossils provides a potential substrate for determining paleoecological and taxonomic relationships based on isotopic and amino acid data. Present criteria for evaluating indigeneity has focused on a bulk organic fraction derived from fossils and includes analysis of amino acid abundances and enantiomers and comparison of the 13C and 15N values of the fossil material to those of the modern organism. These criteria incorporate two assumptions that 1) the bulk organic material is homogeneous and 2) the relative abundance of amino acids and the isotopic compositions are comparable to a modern analog. The difficulties with these assumptions are that the bulk material is not homogeneous but rather composed of several different proteins and the organic matrix of fossils may be altered. If the diagenetic product obtained from a fossil is a consequence of differential loss or retention of specific protein fractions then the geochemical characteristics and interpretation of the data are entirely a function of the protein composition of the organic matrix. Therefore, more precise and new methods are needed to assess the effects of diagenesis and derive criteria for indigeneity. A better understanding of changes in the organic fraction of fossil material over time must include 1) an evaluation of variation in the relative contributions of each of the protein fractions over time, 2) an understanding of the alterations that occur in the biochemical characteristics of individual protein fractions during diagenesis and 3) new molecular level approaches, such as evaluation of the 13C of individual amino acid enantiomers (see Justification of explanation). We anticipate that the proposed research will provide unique information on diagenesis through molecular level analyses on individual proteins.