Atomic force microscopy imaging of supramolecular organization of hyaluronan and its receptor CD44.
Hyaluronan is a major component of extracellular matrix and involved in a variety of important biological processes such as cell motility, proliferation, differentiation, and survival. However, the structure of hyaluronan and the mode of interaction between hyaluronan and its receptor remain to be fully elucidated. Here, we visualized directly the structure of hyaluronan by nanoscale imaging using atomic force microscopy (AFM), and analyzed the pattern of interaction with its cell surface receptor CD44. We observed by AFM that hyaluronan formed honeycomb-like network structures, to which the recombinant protein of CD44 extracellular domain intensively adhered. The pattern of the meshwork varied with the concentration of hyaluronan and also with its molecular weight. These observations suggest that the network structure might account for the properties of hyaluronan of being like an elastic gel at high concentration, and that the structure varying in relation to the molecular weight may cause the difference in the biological activities of the hyaluronan.
Department of Immunology and Microbiology, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan.
Toshiyuki
T
Murai
Hitomi
H
Hokonohara
Akihiko
A
Takagi
Tomoji
T
Kawai
D000818:Animals; D001665:Binding Sites; D004548:Elasticity; D006801:Humans; D018960:Hyaluronan Receptors / Q000737:chemistry*; D006820:Hyaluronic Acid / Q000737:chemistry*; D066298:In Vitro Techniques; D046911:Macromolecular Substances / Q000737:chemistry; D018625:Microscopy, Atomic Force; D015394:Molecular Structure; D008970:Molecular Weight; D009844:Oligosaccharides / Q000737:chemistry; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry
C497483:CD44 protein, human; D018960:Hyaluronan Receptors; D046911:Macromolecular Substances; D009844:Oligosaccharides; D011994:Recombinant Proteins; D006820:Hyaluronic Acid