recal2

recal2 performs internal recalibration of liquid chromatography (LC) coupled Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) datasets by using peptides identified through tandem mass spectrometry (MS/MS) to improve peptide mass measurement accuracy.

Key Features:

• Automated Internal Calibration: Employs an automated method that uses ambient polydimethylcyclosiloxanes as internal calibrants within the mass spectra to calibrate LC/FTICR data.
• MS/MS-guided Reference Points: Uses peptides identified by concurrent MS/MS as reference points for internal calibration of MS1 measurements.
• Mass Accuracy Improvement: Demonstrated reduction of mass measurement error from 4.3 ± 3.7 ppm to 0.3 ± 2.3 ppm in an E. coli LC/FTICR dataset of ~1000 MS and MS/MS spectra.
• Applicability to Complex Digests: Applicable to calibration and analysis of complex protein digests analyzed by FTICRMS for proteomics studies.

Scientific Applications:

• Large-scale Protein Identification: Enables large-scale protein identification from bacterial whole-cell digests by improving mass measurement accuracy to the parts-per-million range.
• High-precision Proteomics: Supports high-precision proteomic analyses by improving MS1 mass accuracy and reducing reliance solely on MS/MS for identification.

Methodology:

Performs automated internal recalibration by using peptides identified in concurrent MS/MS as calibration reference points and incorporating ambient polydimethylcyclosiloxanes as internal calibrants within LC/FTICR datasets.