rakuvälise maatriksi koosseisu kuuluv, suur, mittesulfeeritud ning vee molekulidega seotud glükoosaminoglükaan (GAG) (nimetatakse ka hüaluroonhappeks või hüaluronaadiks), mis koosneb kuni 25000 korduvast disahhariidi järjestusest, Hyaluronic acid (HA; conjugate base hyaluronate), also called hyaluronan, is an anionic, nonsulfated glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. It is unique among glycosaminoglycans in that it is nonsulfated, forms in the plasma membrane instead of the Golgi apparatus, and can be very large, with its molecular weight often reaching the millions.