Interaction characterization of 5-hydroxymethyl-2-furaldehyde with human serum albumin: Binding characteristics, conformational change and mechanism

5-Hydroxymethyl-2-furaldehyde (5-HMF) is a kind of by-product produced in food processing, which may cause latent hazard to human health. Here, the interaction of 5-HMF with human serum albumin (HSA) was studied by multi-spectroscopic methods, multivariate curve resolution-alternating least squares (MCR-ALS) and molecular docking. The formation of 5-HMF-HSA complex was confirmed by MCR-ALS. The fluorescence quenching mechanism of HSA by 5-HMF was static, and their binding constant was 525 x 10(4) L mol(-1) at 298 K, the binding site of 5-HMF was located in subdomain IIA of HSA. The main forces of the interaction were hydrogen bonds and van der Waals forces. The molecular docking showed that three hydrogen bonds were formed between -CH2OH of 5-HMF and Lys106, Pro147 and Gln29 of HSA. The synchronous fluorescence, three-dimensional fluorescence and circular dichroism spectra showed that 5-HMF induced a structural shrinkage of HSA. Fluorescence phase diagram ascertained that the HSA conformational change was in accordance with allor-none model. Moreover, the presence of the food nutrients (vitamin C, chlorogenic acid and phloretin) weakened the binding of 5-HMF with HSA. This study is helpful to understand the hazard mechanism of 5-HMF to human body and provides new strategies to reduce the hazard of 5-HMF. (C) 2019 Elsevier B.V. All rights reserved.