The cellular synthesis of HA is a unique and highly controlled process. Most glycosaminoglycans are made in the cell’s Golgi networks. HA is naturally
synthesized by a class of integral membrane proteins called hyaluronan synthases, of which vertebrates have three types: HAS1, HAS2, and HAS3 (Lee and
Spicer, 2000). Secondary structure predictions and homology modeling indicate an integral membrane protein (IMP). An integral membrane protein is a protein molecule (or assembly of proteins) that in most cases spans the biological membrane with which it is associated (especially the plasma membrane) or which, is sufficiently embedded in the
membrane to remain with it during the initial steps of biochemical purification (in contrast to peripheral membrane proteins). Hyaluronan synthase enzymes synthesize large, linear polymers of the repeating disaccharide structure of hyaluronan by alternate addition of glucuronic acid and N-acetylglucosamine to the growing chain using their activated nucle acetlyglucosamine) as substrates