title: Electrostatic Forces Mediated by Choline Dihydrogen Phosphate Stabilize Collagen.
abstract: Cross-linkers aid in improving biostability of collagen via different mechanisms. Choline dihydrogen phosphate (cDHP), a biocompatible ionic liquid, has been reported as a potential cross-linker for collagen. However, its mechanism is yet unclear. This study explores the effect of cDHP on the physicochemical stability of collagen and nature of its interaction. Dielectric behavior of collagen-cDHP composites signifies that cDHP enhances intermolecular forces. This was demonstrated by an increase in cross-linked groups and high denaturation temperature of collagen-cDHP composites. XRD measurements reveal minor conformational change in helices. Molecular modeling studies illustrate that the force existing between collagen and cDHP is electrostatic in nature. Herein, it is postulated that dihydrogen phosphate anion attaches to cationic functional groups of collagen, resulting in closer vicinity of various side chains of collagen, forming physical and chemical cross-links within collagen, contributing to its structural stability. Our study suggests that dihydrogen phosphate anions can be employed for developing a new class of biocompatible cross-linkers.
authors.affiliation: Chemical Laboratory, CSIR-Central Leather Research Institute , Adyar, Chennai 600020, India.
authors.forename: Ami
authors.initials: A
authors.lastname: Mehta
authors.affiliation: Chemical Laboratory, CSIR-Central Leather Research Institute , Adyar, Chennai 600020, India.
authors.forename: J Raghava
authors.initials: JR
authors.lastname: Rao
authors.affiliation: Chemical Laboratory, CSIR-Central Leather Research Institute , Adyar, Chennai 600020, India.
authors.forename: N Nishad
authors.initials: NN
authors.lastname: Fathima
mesh_terms: D000595:Amino Acid Sequence; D003094:Collagen / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010767:Phosphorylcholine / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity; D014961:X-Ray Diffraction
chemical_list: D010767:Phosphorylcholine; D003094:Collagen