Investigation of binding interaction between bovine α-lactalbumin and procyanidin B2 by spectroscopic methods and molecular docking

Yuting Fan; Qingyu He; Chao Gan; Zhen Wen; Jiang Yi

doi:10.1016/j.foodchem.2022.132509

Investigation of binding interaction between bovine α-lactalbumin and procyanidin B2 by spectroscopic methods and molecular docking

Food Chem. 2022 Aug 1:384:132509. doi: 10.1016/j.foodchem.2022.132509. Epub 2022 Feb 19.

Authors

Yuting Fan¹, Qingyu He², Chao Gan², Zhen Wen², Jiang Yi³

Affiliations

¹ School of Public Health, Health Science Center, Shenzhen University, Shenzhen, Guangdong 518060, China.
² Department of Food Science and Engineering, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China.
³ Department of Food Science and Engineering, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China. Electronic address: jiangyi@szu.edu.cn.

PMID: 35217463
DOI: 10.1016/j.foodchem.2022.132509

Abstract

The interactions between bovine α-lactalbumin and procyanidin B2 were fully investigated by spectroscopic methods and molecular docking. This study hypothesized that ALA could spontaneously interact with procyanidin B2 to form protein-based complex delivery carrier. Far UV CD and FTIR data demonstrated ALA's secondary structures were altered and intrinsic fluorescence quenching suggested ALA conformation was changed with procyanidin B2. Calorimetric technique illustrated ALA-procyanidin B2 complexation was a spontaneous and exothermic process with the number of binding site (n, 3.53) and the binding constant (K_b, 2.16 × 10⁴ M^-1). A stable nano-delivery system with ALA can be formed for encapsulating, stabilizing and delivering procyanidin B2. Molecular docking study further elucidated that hydrogen bonds dominated procyanidin B2 binding to ALA in a hydrophobic pocket. This study shows great potential in using ALA as protein-based nanocarriers for oral delivery of hydrophilic nutraceuticals, because procyanidin B2-loaded ALA complex delivery systems can be spontaneously formed.

Keywords: Complex; Isothermal titration calorimetry; Molecular docking; Procyanidin B2; α-Lactalbumin.

MeSH terms

Animals
Biflavonoids*
Binding Sites
Catechin
Cattle
Lactalbumin* / chemistry
Molecular Docking Simulation
Proanthocyanidins
Protein Binding
Protein Structure, Secondary
Spectrometry, Fluorescence
Thermodynamics

Substances

Biflavonoids
Proanthocyanidins
procyanidin B2
Catechin
Lactalbumin