Recombinant Human Hyaluronidase 1/HYAL1 Protein, CF

Human hyaluronidases (HYALs) are a group of five endo‑ beta‑N‑acetyl‑hexosaminidases that include HYAL1, HYAL2, HYAL3, HYAL4, and SPAM1 (PH20) (1, 2). While HYAL1, HYAL2 and SPAM1 are endo‑ beta‑N‑acetyl‑glucosaminidase that are mainly active on hyaluronan with little activity on chondroitin sulfate (3, 4, 5), HYAL4 is mainly active on chondroitin sulfate (type C and D in particular) (6). Hyaluronan and chondroitin sulfate are abundant extracellular matrix components that have numerous biological functions (7). The backbone of chondroitin sulfate composed of repeating units of ‑4GlcA beta1‑3GalNAc beta1‑ most closely resembles to that of hyaluronan composed of repeating units of ‑4GlcA beta1‑3GlcNAc beta1‑, which may partially explain the overlapping substrate specificity of most hyaluronidases. HYAL1 is a lysosomal hyaluronidase with optimal activity around pH 4.0 (8). It is highly expressed in the liver, kidney and heart, and is the predominant hyaluronidase found in plasma (9). Defects in HYAL1 are associated with mucopolysaccharidosis type IX, or hyaluronidase deficiency (10). Surprisingly, HYAL1 has been reported both as a tumor promoter and suppressor (11, 12).The enzymatic activity of recombinant human HYAL1 was measured using ³⁵S‑labeled hyaluronan as substrate.