Structural insights into the binding mode and conformational changes of BSA induced by bixin and crocin

Abstract

Bixin and crocin are natural apocarotenoids utilized as food colorants and additives in food industries worldwide. For safety assessment, it is necessary to understand the biological interaction of food colorants. In our present study, we report the interaction of two apocarotenoids with bovine serum albumin (BSA) at physiological pH using spectroscopic techniques and in silico tools. The binding constant and the mode of binding sites have been studied. The enthalpic and entropic contribution to the intermolecular binding event was analyzed and it was found that the contribution of hydrogen bonding and hydrophobic interactions was dominant. The adverse temperature dependence in the unusual static quenching is found to be a reasonable consequence of the large activation energy requirement in the binding process, which is required to overcome the fundamental block and is a direct result of the unique microstructure of the binding sites. To confirm the experimental analysis, we investigated the binding patterns using different in silico tools. A combination of molecular docking, molecular dynamics, and toxicity analysis was performed, and the obtained results revealed that both the apocarotenoids had high binding affinity with a binding energy of -5.44 and -5.93 kcal/mol for bixin and crocin, respectively, with no toxic effects and are in accordance with our experimental analysis. The results directly revealed the flexibility of the protein toward bixin and crocin which has a great impact on the interaction. Thus bixin and crocin can guardedly be used as food colorants in food industries.

Unraveling the molecular mechanisms underlying interactions between caseins and lutein

“…In general, investigations on the interactions between proteins and carotenoids have focused on protein conformational changes (Li, Wang, Chen, & Lu, 2015;Mohan, Hemachandran, Sneha, Doss, & Godwin Christopher, Jayaraman, Gurunathan, & Ramamoorthy, Siva, 2018;Mora-Gutierrez et al, 2018;Yi, Fan, Yokoyama, Zhang, & Zhao, 2016). Some papers reported the potential of caseinate as carotenoid nanocarrier.…”

Understanding the molecular interaction of human argonaute‐2 and miR‐20a complex: A molecular dynamics approach

“…A recent study using molecular docking and MD showed the binding mode and conformational changes of bovine serum albumin (BSA) interaction with natural apocarotenoids, bixin, and crocin. The study revealed structural insights of BSA binding flexibility with the bixin and crocin . Another study utilizing molecular docking and MD illustrated a compound 19583672 having potent inhibitory activity against resistant enzyme in drug‐resistant Klebsiella pneumonia .…”

“…miRNA, microRNA; mRNA, messenger RNA flexibility with the bixin and crocin. 53 Another study utilizing molecular docking and MD illustrated a compound 19583672 having potent inhibitory activity against resistant enzyme in drug-resistant Klebsiella pneumonia. 54 Carotenoid cleavage dioxygenase (CCD) gene is important for plant and is responsible for synthesizing various volatile compounds called as apocarotenoids.…”

Crocin induces autophagic cell death and inhibits cell invasion of cervical cancer SiHa cells through activation of PI3K/AKT

“…Based on these results, they argued that the adverse effects of crocin might limit its clinical application. However, crocin has long been utilized as a food colorant and additive in the food industry worldwide, which strongly supports its safety profile (33). On the other hand, less protein/peptides and more glucose or TG in serum may be of benefit in combating tumors, as the protein supply of tumors can be limited and the immune system can be activated.…”