44,000 Protein Forms Mapped in Plasma

DIA mass spectrometry maps extensive proteoform diversity in human plasma

October 19, 2026
3 min

The Analytical Scientist

At a Glance

Category	Detail
Condition	Human plasma proteoform diversity
Key Mechanisms	Proteoforms arise through processes including alternative splicing, protein cleavage, and post-production chemical modifications.
Target Population	Human plasma samples analyzed in a proteomics study; the article does not specify a clinical patient population.
Care Setting	Laboratory proteomics and biomarker research using plasma samples.

Key Highlights

The workflow detected 179,049 potential proteoforms across 5,077 protein groups; 44,083 proteoforms from 2,089 groups met the study’s high-confidence criterion.
High-confidence proteoforms were detected in at least three of four replicate gel experiments; the median was 11 per protein.
Proteoform diversity was greatest among abundant proteins and proteins involved in nutrient transport, blood clotting, and the complement immune system.
Agreement between Olink and SomaScan measurements was generally closer for relatively abundant proteins with low or moderate proteoform diversity.
The atlas is an initial reference: most proteoforms were not fully identified at the molecular level, and low-abundance or disease-associated forms may be underrepresented.

Guideline-Based Recommendations

Diagnosis

Management

Monitoring & Follow-up

Risks

Affinity-based assays designed to measure the same protein may recognize different proteoforms, affecting comparisons between technologies and interpretation of results.
Poor agreement between Olink and SomaScan was most often associated with low protein concentrations; high proteoform diversity may explain some discrepancies involving more abundant proteins.
The analysis may include proteins introduced through cellular contamination, and some findings may represent groups of closely related proteoforms rather than individual molecules.

Patient & Prescribing Data

No treatment or prescribing population is described; the study analyzed human plasma proteomes.

The article reports no treatments or prescribing data. It notes that proteoform differences may affect biomarker assay comparisons and interpretation.

Clinical Best Practices

When comparing affinity-based proteomic measurements, account for the possibility that assays targeting the same protein may recognize different proteoforms.
Interpret the atlas as an initial reference rather than a complete account of the plasma proteome.
The researchers state that further studies using top-down mass spectrometry, clinical cohorts, and samples from different populations are needed to assess proteoform associations with normal biology and disease.