Analysis of Stable Isotope Assisted Metabolomics Data Acquired by High Resolution Mass Spectrometry

Area of Science:

• Biochemistry
• Analytical Chemistry
• Metabolomics

Background:

• Stable isotope assisted metabolomics (SIAM) is crucial for elucidating biochemical pathways.
• Existing SIAM data analysis methods often require manual intervention and can lack accuracy.
• High-resolution mass spectrometry generates complex datasets that necessitate robust analytical tools.

Purpose of the Study:

• To develop and validate a suite of automated data analysis algorithms for SIAM.
• To enhance the accuracy of isotopologue assignment and deconvolution of isotopic peaks.
• To implement a normalization method for comparing isotopologue abundance between sample groups.

Main Methods:

• Utilized reference metabolites from unlabeled samples to generate isotopologue candidates for labeled samples.
• Developed an iterative linear regression model for deconvoluting overlapping isotopic peaks in MS spectra.
• Implemented isotope ratio-based normalization for comparative analysis of isotopologue abundance distributions.
• Validated algorithms using known compound mixtures and complex biological samples.

Main Results:

• The developed algorithms accurately identify metabolites and quantify stable isotope enrichment.
• The method effectively deconvolutes overlapping isotopic peaks, improving isotopologue assignment accuracy.
• Isotope ratio-based normalization successfully highlights differences in isotopologue abundance between sample groups.
• The algorithms demonstrated effectiveness and accuracy in both direct infusion MS and LC-MS data.

Conclusions:

• A comprehensive suite of automated algorithms for SIAM data analysis has been successfully developed.
• The new methods significantly improve the accuracy and efficiency of metabolite identification and isotope enrichment quantification.
• The developed SIAM analysis pipeline is versatile, handling various tracer elements and MS acquisition methods.
• This work provides a powerful tool for advancing biochemical mechanism studies using stable isotope tracers.