Characterization and effects of binding of food-derived bioactive phycocyanobilin to bovine serum albumin
Characterization and effects of binding of food-derived bioactive phycocyanobilin to bovine serum albumin
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DOI：
10.1016/j.foodchem.2017.07.066
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发表时间：
2018-01-12
期刊：
影响因子：
8.8
通讯作者：
Velickovic, Tanja Cirkovic
中科院分区：
文献类型：
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作者：
Minic, Simeon;Stanic-Vucinic, Dragana;Velickovic, Tanja Cirkovic
藻蓝胆素（PCB）是c -藻蓝蛋白的蓝色四吡啶发色团，藻蓝蛋白是微藻螺旋藻的主要蛋白质，具有许多已证实的健康相关益处。我们研究了PCB与牛血清白蛋白（BSA）的结合，以及它如何影响蛋白质和配体的稳定性。蛋白质荧光猝灭和微尺度热泳术显示出高亲和力结合（K-a = 2 × 10(6) M-1）。分子对接分析的光谱滴定显示了BSA上的两个结合位点，即域间间隙和亚域IB，而CD光谱显示了色素的P构象与蛋白质的立体选择性结合。PCB蛋白复合物显示出更高的热稳定性。虽然络合物的形成部分掩盖了PCB和BSA的抗氧化性能，但发现它们对自由基诱导的氧化具有相互保护作用。BSA可以作为食品着色剂或生物活性成分适用于PCB的递送。我们的结果还强调了PCB与牛和人血清白蛋白结合之间的细微差异。(C) 2017 Elsevier Ltd.版权所有。
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 (K-a = 2 x 10(6) 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 binding to bovine vs. human serum albumin. (C) 2017 Elsevier Ltd. All rights reserved.