Force spectroscopy of hyaluronan by atomic force microscopy: from hydrogen-bonded networks toward single-chain behavior.
The conformational behavior of hyaluronan (HA) polysaccharide chains in aqueous NaCl solution was characterized directly at the single-molecule level. This communication reports on one of the first single-chain atomic force microscopy (AFM) experiments performed at variable temperatures, investigating the influence of the temperature on the stability of the HA single-chain conformation. Through AFM single-molecule force spectroscopy, the temperature destabilization of a local structure was proven. This structure involved a hydrogen-bonded network along the polymeric chain, with hydrogen bonds between the polar groups of HA and possibly water, and a change from a nonrandom coil to a random coil behavior was observed when increasing the temperature from 29 +/- 1 to 46 +/- 1 degrees C. As a result of the applied force, this superstructure was found to break progressively at room temperature. The use of a hydrogen-bonding breaker solvent demonstrated the hydrogen-bonded water-bridged nature of the network structure of HA single chains in aqueous NaCl solution.
Giannotti
Marina I
MI
Department of Materials Science and Technology of Polymers and MESA+ Research Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
Rinaudo
Marguerite
M
Vancso
G Julius
GJ
D006820:Hyaluronic Acid / Q000737:chemistry*; D006860:Hydrogen Bonding; D018625:Microscopy, Atomic Force; D015394:Molecular Structure; D013057:Spectrum Analysis
D006820:Hyaluronic Acid