Adding Color to Mass Spectra of Biopolymers: Charge Determination Analysis (CHARDA) Assigns Charge State to Every Ion Peak

• Published in: Journal of the American Society for Mass Spectrometry Vol. 35; no. 5; pp. 902 - 911
• Main Authors: Lyutvinskiy, Yaroslav, Nagornov, Konstantin O., Kozhinov, Anton N., Gasilova, Natalia, Menin, Laure, Meng, Zhaowei, Zhang, Xuepei, Saei, Amir Ata, Fu, Tingting, Chamot-Rooke, Julia, Tsybin, Yury O., Makarov, Alexander, Zubarev, Roman A.
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 01-05-2024
• Subjects: Analytical chemistry; Biochemistry; Biochemistry, Molecular Biology; Biopolymers - analysis; Biopolymers - chemistry; Chemical Sciences; Color; Fourier Analysis; Ions - chemistry; Life Sciences; Medicin och hälsovetenskap; Tandem Mass Spectrometry - methods; mass spectrometry; polypeptide; proteomics; spectrum
• ISSN: 1044-0305; 1879-1123; 1879-1123
• DOI: 10.1021/jasms.3c00442

Traditionally, mass spectrometry (MS) output is the ion abundance plotted versus the ionic mass-to-charge ratio m/z. While employing only commercially available equipment, Charge Determination Analysis (CHARDA) adds a third dimension to MS, estimating for individual peaks their charge states z starting from z = 1 and color coding z in m/z spectra. CHARDA combines the analysis of ion signal decay rates in the time-domain data (transients) in Fourier transform (FT) MS with the interrogation of mass defects (fractional mass) of biopolymers. Being applied to individual isotopic peaks in a complex protein tandem (MS/MS) data set, CHARDA aids peptide mass spectra interpretation by facilitating charge-state deconvolution of large ionic species in crowded regions, estimating z even in the absence of an isotopic distribution (e.g., for monoisotopic mass spectra). CHARDA is fast, robust, and consistent with conventional FTMS and FTMS/MS data acquisition procedures. An effective charge-state resolution R z ≥ 6 is obtained with the potential for further improvements.