Measuring proteins in H₂O using 2D-IR spectroscopy: pre-processing steps and applications toward a protein library

Area of Science:

• Biophysical Chemistry
• Spectroscopy
• Analytical Chemistry

Background:

• Two-dimensional infrared (2D-IR) spectroscopy can analyze proteins in aqueous solutions, enabling in vivo studies.
• Standardization is crucial for comparing 2D-IR datasets in analytical applications like diagnostics and protein screening.

Purpose of the Study:

• To develop a pre-processing workflow for 2D-IR data to improve spectral cross-comparisons.
• To enable robust quantification of proteins in complex biological samples.

Main Methods:

• A novel pre-processing workflow utilizing the thermal water signal for baseline correction and normalization.
• Integration of Principal Component analysis for noise reduction.
• Application to previously published data and a pilot study for serum protein quantification.

Main Results:

• The workflow demonstrated improved quantification accuracy and detection limits on existing datasets.
• Successful label-free quantification of four major protein constituents in blood serum using a prototype spectral library.
• Validation of the workflow's effectiveness in handling complex biological samples.

Conclusions:

• The developed pre-processing workflow significantly enhances the reliability and applicability of 2D-IR spectroscopy.
• This advancement paves the way for routine use of 2D-IR in pharmaceutical and biomedical analyses.
• Robust data handling strategies are essential for future diagnostic and screening applications of 2D-IR.