The role of the solvent on proton localization and zwitterion formation in amino acids and small peptides: influence on structure and dynamics

合作的主题是了解中性和电离氨基酸以及气相小肽中的质子或氢转移反应。这些过程受分子内性质的控制，但同样受到溶剂的影响甚至催化。方法论方法是利用光谱结构数据深入解释关于FAST(纳秒)和超快(FS)时间尺度的动力学研究。从基本的观点来看，目标是跟踪分子体系性质的演变，作为它们周围的溶剂分子数量的函数。这四个小组在利用初级模型系统进行此类研究方面有着长期的经验，并建议将其扩展到蛋白质组分。质子转移的不同方面：质子局部化、两性离子的形成、电荷迁移和碎裂，将通过互补的方法进行研究。一个单一的实验不能单独为研究的问题提供完整的答案。例如，中性和带电的氨基酸或多肽不能用相同的实验技术处理。参赛队已经制定了一些实验方法，并将从一个小组转移到另一个小组(例如，红外耗尽)。其他一些到目前为止从未使用过，它们需要不同团队的充分合作(例如，多肽的时间分辨碎裂，同时检测离子和中性产物)。该合作计划将研究先进质谱学的一个长期目标的可行性：引入激光控制的蛋白质片段选择性解离，通过红外光谱提供片段和非共价复合体的结构信息，一直到单离子检测水平，用于蛋白质组学中的蛋白质测序。

The subject of the collaboration is the understanding of proton or hydrogen transfer reactions in neutral and ionized amino acids and small peptides in the gas phase. These processes are controlled by intramolecular properties but are equally influenced or even catalyzed by the solvent. The methodological approach is the use of spectroscopic structural data for the in-depth interpretation of dynamical studies on fast (ns) and an ultra-fast (fs) time-scale. From a fundamental point of view, the aim is to follow the evolution of the properties of molecular systems as a function of the number of solvent molecules which surround them. The four groups have a long-standing experience of such studies with elementary model systems and propose to extend them to protein components. The different aspects of proton transfer: proton localization, zwitterion formation, charge migration and fragmentation, will be investigated by means of complementary approaches. A single experiment cannot alone provide a full answer to the studied problems. For example, neutral and charged amino acids or peptides cannot be handled with the same experimental techniques. Some experimental approaches have already been developed by the participating teams and will be transferred from one group to another (e.g. IR depletion). Some others have up to now never been used and they will require the full cooperation of the different teams (e.g. time-resolved fragmentation of peptides with simultaneous detection of ionic and neutral products). The cooperation program will investigate the feasibility of a long-standing goal of advanced mass-spectrometry: the introduction of laser-controlled selective dissociation of protein fragments to provide structural information on fragments and non-covalent complexes through IR spectroscopy, down to the single ion detection level, for protein-sequencing in Proteomics.