Recombinant bovine serum albumin domain II as bioreceptor for ochratoxin A capture
Year: 2024
Type: article
Abstract: Established chromatographic techniques for mycotoxin control in foodstuffs require prior sample enrichment and clean-up, typically achieved using immunoaffinity columns (IACs). Bovine serum albumin (BSA) has recently emerged as a cost-effective alternative to antibodies used in IACs. This study aimed at exploring the BSA domain II (BDII), which houses the primary binding site for ochratoxin A (OTA), as a bioreceptor for OTA capture. Recombinant BDII (rBDII) was produced in soluble form by Escherichia coli Origami 2(DE3), fused to a His6 (HisBDII) or thioredoxin-His6 (TrxBDII) tag, with yields up to 19 ± 4.3 mg/L culture in shake-flask. Fluorescence and circular dichroism (CD) spectroscopy revealed interaction of OTA with both rBDII variants, with estimated binding constants for OTA-HisBDII/TrxBDII complexes in the range of 5.7–9.3 × 10 4 M −1 . CD also showed an α/β structure of rBDII variants, in opposition to the predominant α-helical structure of whole BSA, and slight increase in their α-helical content upon binding to OTA. TrxBDII immobilized on Ni-NTA resin successfully captured OTA from spiked samples at the optimum pH range of 6.5–7.0, allowing OTA extraction, clean-up, and enrichment from spiked white grape juice, with up to 84 ± 7.4 % recovery. • BSA domain II (rBDII) fusions obtained from E. coli interact with ochratoxin A (OTA). • OTA induces slight increase in the α-helical content of α/β rBDII fusions. • Trx-His6-tagged rBDII (TrxBDII) immobilized on Ni-NTA resin keeps OTA-binding ability. • TrxBDII-based SPE columns successfully captured OTA from spiked white grape juice. • SPE using TrxBDII as bioreceptor enabled OTA extraction, clean-up, and enrichment.
Source: Talanta
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: hybrid
Estimated APC paid: $4,290
OpenAlex ID: W4403928034