High voltage atmospheric cold plasma modification of bovine serum albumin

• Published in: Food science & technology Vol. 149; p. 111995
• Main Authors: Xu, Lei, Hou, Hu, Farkas, Brian, Keener, Kevin M., Garner, Allen L., Tao, Bernard
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-09-2021
• Subjects: Bovine serum albumin; Cold plasma; Protein modification; Bovine serum albumin; Cold plasma; Protein modification
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2021.111995

While atmospheric cold plasma has successfully inactivated biohazardous proteinaceous molecules (unwanted enzymes, prions, and allergens) and modified proteins with improved functionality, few studies have characterized plasma-protein interactions. This study investigates the physicochemical interactions, structural alteration, and reaction mechanisms of bovine serum albumin (BSA) subjected to high voltage atmospheric cold plasma (HVACP) generated by a dielectric barrier discharge in sealed bags packed with air or modified air (65% O2, 30% N2, 5% CO2). Treating 10 mL of BSA solution (50 mg/mL) with HVACP for 60 min changed the sample from transparent to yellow and induced protein precipitation. HVACP also induced protein unfolding, altered secondary structure (27% loss of α-helix), and increased disorder structure (10% increase of random coil). HVACP-treated protein increased in average size from 10 nm to 113 μm, with a broader size distribution after 60 min of HVACP treatment. SDS-PAGE and mass spectrometry showed the formation of new peptides from 1 to 10 kDa, indicating plasma-triggered peptide bond cleavage. Chemical analysis and mass spectrometry demonstrated oxidation and deamidation in HVACP-treated samples. This study illustrates that interactions between HVACP-induced reactive species and proteins may introduce structural alterations, protein aggregation, peptide cleavage, and side-group modifications to proteins in aqueous conditions.
High voltage atmospheric cold plasma (HVACP) induces protein structure changes.HVACP induced side-group modifications, such as oxidation and deamidation.HVACP induced protein unfolding, denaturation, aggregation, and precipitation.HVACP-triggered peptide bond cleavage generated new peptides from 1 to 10 kDa.