Characterization and effects of binding of food-derived bioactive phycocyanobilin to bovine serum albumin
AuthorsMinić, Simeon L.
Radomirović, Mirjana Ž.
Milčić, Miloš K.
Conference object (Published version)
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Phycocyanobilin (PCB) is a blue tetrapyrrole chromophore of C-phycocyanin, the main protein of the microalga Spirulina, with numerous proven health-related benefits. We examined binding of PCB to bovine serum albumin (BSA) and how it affects protein and ligand stability. Protein fluorescence quenching and microscale thermophoresis demonstrated high-affinity binding (Ka = 2 × 106 M−1). Spectroscopic titration with molecular docking analysis revealed two binding sites on BSA, at the inter-domain cleft and at subdomain IB, while CD spectroscopy indicated stereo-selective binding of the P conformer of the pigment to the protein. The PCB protein complex showed increased thermal stability. Although complex formation partly masked the antioxidant properties of PCB and BSA, a mutually protective effect against free radical-induced oxidation was found. BSA could be suitable for delivery of PCB as a food colorant or bioactive component. Our results also highlight subtle differences between PCB b...inding to bovine vs. human serum albumin.
Keywords:Antioxidant / Binding / Bovine serum albumin / Phycocyanobilin / Spirulina / Stability
Source:FEBS Journal / Federation of European of Biochemical Societies, 2017, 284, 189-190
- Wiley, Hoboken