Tapping mode atomic force microscopy of hyaluronan: extended and intramolecularly interacting chains.
The extracellular matrix polysaccharide hyaluronan has been examined by tapping mode atomic force microscopy. High molecular weight hyaluronan was deposited on mica from dilute aqueous solution and imaged in air. Long unbranched chains could be observed and were found to be compatible with the known covalent structure of hyaluronan. In addition, chains with evidence of intramolecular association were observed. In the simplest cases, the association took the form of loops stabilized by antiparallel double-stranded (probably double-helical) segments. In other cases, the polarity of the associated regions could not be determined. Extensive intramolecular association in long hyaluronan chains resulted in a fenestrated structure of the same type as that formed by intermolecular association at higher concentrations.
Cowman
M K
MK
Department of Chemical Engineering, Chemistry, and Materials Science and Herman F. Mark Polymer Research Institute, Polytechnic University, Brooklyn, New York 11201, USA. mcowman@duke.poly.edu
Li
M
M
Balazs
E A
EA
D000818:Animals; D002236:Carbohydrate Conformation; D002645:Chickens; D003129:Comb and Wattles; D006820:Hyaluronic Acid / Q000648:ultrastructure*; D008297:Male; D018625:Microscopy, Atomic Force / Q000379:methods*
D006820:Hyaluronic Acid