Hyaluronic Acid: A Novel, Double Helical Molecule

Films prepared from a deformable gel (or putty) of hyaluronic acid show high crystallinity and orientation in their x-ray diffraction patterns. We have derived a probable structure for the molecules in these films. This is a double helix in which two identical, left-handed strands are antiparallel to one another. Each strand has four disaccharide residues per pitch length. Although the putty is prepared at p H 2.5, at which dilute solutions of hyaluronic have exaggerated rheological properties, the double helical form can also exist at physiological p H and therefore may be a biologically important form.