Department of Chemistry , University of Texas at Austin , Austin , Texas 78712 , United States.
Thermo Fisher Scientific Inc. , 355 River Oaks Parkway , San Jose , California 95134 , United States.
Anal Chem. 2018 Jul 17;90(14):8583-8591. doi: 10.1021/acs.analchem.8b01723. Epub 2018 Jul 6.
Ultraviolet photodissociation (UVPD) is a nonselective activation method in which both precursor and fragment ions may absorb photons and dissociate. Photoactivation of fragment ions may result in secondary or multiple generations of dissociation, which decreases the signal-to-noise ratio (S/N) of larger fragment ions owing to the prevalent subdivision of the ion current into many smaller, often less informative, fragment ions. Here we report the use of dipolar excitation waveforms to displace fragment ions out of the laser beam path, thus alleviating the extent of secondary dissociation during 193 nm UVPD. This fragment ion protection (FIP) strategy increases S/N of larger fragment ions and improves the sequence coverage obtained for proteins via retaining information deeper into the midsection of protein sequences.
紫外光解吸（UVPD）是一种非选择性的激活方法，其中前体离子和碎片离子都可能吸收光子并发生解离。碎片离子的光激活可能导致二级或多级解离，这会由于离子电流普遍分为许多较小的、通常信息量较少的碎片离子，从而降低较大碎片离子的信噪比（S/N）。在这里，我们报告使用偶极激发波形将碎片离子移出激光束路径，从而减轻 193nmUVPD 过程中的二级解离程度。这种碎片离子保护（FIP）策略增加了较大碎片离子的 S/N，并通过保留蛋白质序列中段的信息，提高了通过保留蛋白质序列中段的信息，提高了通过保留蛋白质序列中段的信息，提高了通过保留蛋白质序列中段的信息，提高了蛋白质的序列覆盖度。
