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.
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http://dx.doi.org/10.1021/acs.analchem.8b01723 | DOI Listing |
Methods Mol Biol
January 2025
Department of Medicine and Surgery, Proteomics and Metabolomics Unit, University of Milano-Bicocca, Vedano al Lambro, Italy.
Trapped ion mobility spectrometry (TIMS) using parallel accumulation serial fragmentation (PASEF) is an advanced analytical technique that offers several advantages in mass spectrometry (MS)-based lipidomics. TIMS provides an additional dimension of separation to mass spectrometry and accurate collision cross-section (CCS) measurements for ions, aiding in the structural characterization of molecules. This is especially valuable in lipidomics for identifying and distinguishing isomeric or structurally similar compounds.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
January 2025
Department of Forensic Toxicology, Shanghai Key Laboratory of Forensic Medicine, Shanghai Forensic Science Platform, Academy of Forensic Science, Shanghai 200063 China. Electronic address:
Introduction: Phencyclidine, a dissociative anesthetic with hallucinogenic effects, is commonly abused as a recreational drug. Phencyclidine analogs are compounds produced by substitutions of the phenyl and piperidine rings of phencyclidine. Illegal use of phencyclidine and its analogs has symptoms such as addiction, confusion, and increased tendencies toward violence.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
December 2024
Thirdgrade Pharmacological Laboratory on Traditional Chinese Medicine, State Administration of Traditional Chinese Medicine, China Three Gorges University Yichang 443002, China College of Medicine and Health Sciences, China Three Gorges University Yichang 443002, China.
In this study, the chemical components of Panacis Japonici Rhizoma extract and absorbed components in rats were identified by ultra-high performance liquid chromatography-quadrupole exactive orbitrap mass spectrometry(UPLC-Q-Exactive Orbitrap-MS). The separation was performed by gradient elution on Waters UPLC BEH C_(18) column(2.1 mm×100 mm, 1.
View Article and Find Full Text PDFJ Am Soc Mass Spectrom
January 2025
MS Proteomics Research Group, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok körútja 2, H-1117 Budapest, Hungary.
In recent years, alternative enzymes with varied specificities have gained importance in MS-based bottom-up proteomics, offering orthogonal information about biological samples and advantages in certain applications. However, most mass spectrometric workflows are optimized for tryptic digests. This raises the questions of whether enzyme specificity impacts mass spectrometry and if current methods for nontryptic digests are suboptimal.
View Article and Find Full Text PDFMass Spectrom Rev
January 2025
Department of Chemistry, University of Texas at Austin, Austin, Texas, USA.
Mass spectrometry (MS) has become a critical tool in the characterization of covalently modified nucleic acids. Well-developed bottom-up approaches, where nucleic acids are digested with an endonuclease and the resulting oligonucleotides are separated before MS and MS/MS analysis, provide substantial insight into modified nucleotides in biological and synthetic nucleic. Top-down MS presents an alternative approach where the entire nucleic acid molecule is introduced to the mass spectrometer intact and then fragmented by MS/MS.
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