Hesperidin interaction to collagen detected by physico-chemical techniques
Noriko Hiraishi, Takahiro Maruno, Naoya Tochio, Ryohei Sono, Masayuki Otsuki, Tsutomu Takatsuka, Junji Tagami, Yuji Kobayashi
Dentin collagen can be modified by some plant-derived flavonoids to improve properties of dentin organic matrix. Hesperidin (HPN), a hesperetin-7-O-rutinoside flavonoid, has a potential of dentin modification for being based on evidence that a treatment with HPN may resist collagenase degradation and arrest demineralization of human dentin. In this study, biophysical and molecular-level information on the interaction of HPN and collagen was investigated. HPN is extracted from citrus fruits. Sample collagenous solution was prepared using atelocollagen (ATCL) as a triple-helical peptide model. We have performed circular dichroism spectroscopic analysis, sedimentation velocity measurement by ultracentrifuge and saturation transfer difference measurement (STD) by NMR on HPN-collagen in solution state. The circular dichroism and sedimentation velocity measurement showed the evidence for the molecular interaction between ATCL and HPN, while HPN did not induce any conformational change of ATCL. The STD-NMR study further confirmed this interaction and suggested that HPN interacted with ATCL through its aromatic part, not through its disaccharide moiety. These findings indicated that HPN is weakly bound to ATCL not causing structural modification of collagen. This interaction may contribute to the preservation of collagen by protecting from collagenase degradation.
Circular dichroism, Secondary structure, Thermal stability, Biochemistry, Materials