Discriminative Identification of SARS-CoV-2 Variants Based on Mass-Spectrometry Analysis.

Area of Science:

• Virology
• Analytical Chemistry
• Biotechnology

Background:

• Genetic mutations in SARS-CoV-2 variants of concern (VOCs) can increase transmissibility, disease severity, and immune evasion, impacting diagnostics and vaccine efficacy.
• Current gold-standard genetic sequencing for variant discrimination is time-consuming and costly.
• Rapid and specific diagnostic methods are crucial for managing the spread of SARS-CoV-2 VOCs.

Purpose of the Study:

• To develop and validate a rapid, cost-effective Mass Spectrometry (MS)-based methodology for the universal identification and variant-specific discrimination of SARS-CoV-2.
• To establish a proof-of-concept for MS-based diagnosis using representative VOCs.

Main Methods:

• Development of an MS-based methodology for SARS-CoV-2 diagnosis.
• Identification of conserved peptides for universal SARS-CoV-2 detection.
• In-silico identification of variant-specific tryptic peptides from spike (S) and nucleocapsid (N) proteins.
• Tryptic digest and HR-LC-MS/MS analysis of cell-cultured SARS-CoV-2 variants.
• Validation against the wild-type Wuhan reference strain.

Main Results:

• The MS-based methodology successfully identified SARS-CoV-2 universally and discriminated between specific variants.
• At least two unique peptide markers, primarily from S and N proteins, were identified for each tested VOC.
• The method demonstrated specificity, rapidity, ease of performance, and cost-effectiveness.

Conclusions:

• The developed MS-based methodology provides a rapid, specific, and inexpensive tool for diagnosing SARS-CoV-2 and discriminating between pathogenic variants.
• This approach offers a viable alternative to traditional sequencing for variant surveillance and diagnostics.