Analysis of large biomolecules and biomolecular complexes by TOF mass spectrometry

拟议的研究计划旨在开发改进的质谱学方法，用于识别和表征大的生物分子和生物分子络合物。这些方法将应用于各种生物学问题，使用创新设计的飞行时间(TOF)质谱仪，由我们自己的实验室建造，或与我们的研究伙伴MDS Sciex合作。他说，这种科学的方法利用了TOF仪器测量质量的优势，包括有效地不受限制的m/z范围、快速响应和高灵敏度。我们的实验室有电喷雾和MALDI(基质辅助激光解吸/电离)离子源连接到TOF质谱仪；这两种技术经常提供关于生物分子的互补信息。此后，我们计划继续我们广泛的蛋白质和多肽测序计划，使用混合QqTOF质谱仪(由Sciex和我们合作设计)，它具有一个新的目标组件，可以在计算机控制下以更高的速度和精度定位MALDI目标上的斑点。这种测量通常遵循复杂生物混合物的离线色谱分离。随后，我们还计划将最近发现的电子捕获方法与我们实验室中更新的TOF仪器进行耦合，如随附的“研究工具和仪器”申请中所述。这种解离母体离子的技术往往会沿着主链裂解多肽，保持侧链不变，因此它是对通常的碰撞诱导解离的重要补充，特别是对于修饰的多肽。他说：我们实验室的第二项主要活动是研究非共价化合物。我们最近在实验室建造了一台专门为此目的而设计的正交注入质谱仪，从而提高了我们研究这些重要结构的能力。特别是，这台仪器的加速电压比我们以前的要高得多(16KV比4KV)，这保证了对典型的非共价离子的灵敏度增加了一个数量级。

The proposed research program aims to develop improved mass spectrometric methods for identifying and characterizing large biomolecules and biomolecular complexes. These methods will be applied to various biological problems using time-of-flight (TOF) mass spectrometers of innovative design, constructed in our own laboratory, or in cooperation with our research partner MDS Sciex.      The scientific approach exploits the advantages of TOF instruments for measuring masses, including effectively unlimited m/z range, rapid response, and high sensitivity. Our laboratory has both electrospray and MALDI (matrix-assisted laser desorption/ionization) ion sources coupled to TOF mass spectrometers; the two techniques often provide complementary information about biological molecules.      We plan to continue our extensive program of protein and peptide sequencing, using the hybrid QqTOF mass spectrometer (a cooperative design effort by Sciex and ourselves), which has a new target assembly that enables location of spots on a MALDI target under computer control with much higher speed and accuracy.  Such measurements normally follow the off-line chromatographic separation of complex biological mixtures.      We also plan to couple the recently-discovered electron capture method to a rejuvenated TOF instrument in our laboratory, as described in the accompanying "Research Tools and Instruments" application. This technique for dissociating parent ions tends to cleave peptides along their backbones, leaving the side chains intact, so it is an important complement to the usual collision-induced dissociation, particularly for modified peptides.      A second major activity in our laboratory has been the study of noncovalent complexes. Our ability to investigate these important structures has recently been improved by the construction in our laboratory of an orthogonal injection mass spectrometer specifically designed for the purpose. In particular, this instrument has much higher acceleration voltage than our previous one (16kV vs 4kV), which promises an order of magnitude increase in sensitivity for a typical noncovalent ion.