Evaluation of a Dual Isolation Width Acquisition Method for Isobaric Labeling Ratio Decompression.

Area of Science:

• Proteomics
• Analytical Chemistry
• Biochemistry

Background:

• Isobaric labeling techniques offer precise protein quantification.
• Isolation interference at the MS2 level causes ratio underestimation in isobaric tagging.
• Narrow isolation widths reduce interference but limit proteome coverage.

Purpose of the Study:

• To address the isolation interference problem in isobaric tagging.
• To develop a method that enhances quantification accuracy without compromising proteome coverage.
• To improve the reliability of protein quantification in complex biological samples.

Main Methods:

• Designed a dual isolation width acquisition (DIWA) method.
• Employed two MS2 HCD scans: one standard width for identification/preliminary quantification, and one narrow width for reduced interference quantification.
• Utilized linear regression models to decompress fold-changes from standard scans using narrow scan data.

Main Results:

• The DIWA method was evaluated using a nested two species/gene knockout TMT-6plex design.
• Demonstrated the retention of reporter ion signals even with narrow isolation windows.
• Showcased the ability to decompress fold-changes, indicating improved quantification accuracy.

Conclusions:

• The DIWA method effectively mitigates isolation interference in isobaric labeling.
• This approach offers a promising solution for accurate protein quantification in proteomics.
• DIWA enhances the precision of quantitative proteomics by reducing ratio underestimation.