Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA.
J Am Soc Mass Spectrom. 2017 Sep;28(9):1823-1826. doi: 10.1007/s13361-017-1721-0. Epub 2017 Jul 12.
Top-down ultraviolet photodissociation (UVPD) allows greater sequence coverage than any other currently available method, often fracturing the vast majority of peptide bonds in whole proteins. At the same time, UVPD can be used to dissociate noncovalent complexes assembled from multiple proteins without breaking any covalent bonds. Although the utility of these experiments is unquestioned, the mechanism underlying these seemingly contradictory results has been the subject of many discussions. Herein, some fundamental considerations of photochemistry are briefly summarized within the context of a proposed mechanism that rationalizes the experimental results obtained by UVPD. Considerations for future instrument design, in terms of wavelength choice and power, are briefly discussed. Graphical Abstract ᅟ.
自上而下的紫外光解（UVPD）比目前任何可用的方法都能提供更大的序列覆盖度，通常会使整个蛋白质中的绝大多数肽键断裂。同时，UVPD 可用于解离由多个蛋白质组装而成的非共价复合物，而不会打断任何共价键。尽管这些实验的实用性毋庸置疑，但这些看似矛盾的结果背后的机制一直是许多讨论的主题。本文简要总结了光化学的一些基本考虑因素，并提出了一个机制，该机制合理化了 UVPD 获得的实验结果。还简要讨论了未来仪器设计在波长选择和功率方面的考虑因素。
