Characterisation of Norway lobster (Nephrops norvegicus) hyaluronidase and comparison with sheep and bovine testicular hyaluronidase

The enzyme used in this study was a partially purified sample of hyaluronidase, extracted and purified from Nephrops norvegicus (scampi) hepatopancreas, by acetone fractionation followed by ion-exchange chromatography on Amberlite™IRA 420 and gel filtration on Sephacryl™S-200-HR. The optimum pH varied according to the buffer system, with highest activity being recorded at pH 5.4 in 50 mM sodium-acetate buffer. The enzyme also required NaG at a concentration of 120 mM in the final incubation mixture for optimum activity. Its molecular weight, estimated by gel filtration was 320 kDa and its Km value was 0.42 mg/ml using sodium-hyaluronate from bovine trachea as substrate. The enzyme demonstrated specificity for hyaluronic acid as substrate and showed no activity towards closely related sulphated polysaccharides, chondroitin sulphate A, B or C. On the other hand, the sulphated polysaccharides were found to inhibit scampi hyaluronidase to varying degrees. All enzyme activity was lost on freezing the purified extract to 60°C but addition of dimethyl-sulfoxide (1%) or bovine serum albumin prior to freezing prevented this loss. Scampi hyaluronidase was characterised and compared to commercially available sheep and bovine hyaluronidase. Its specific activity was nearly twice as high as that of the commercial samples. However, scampi hyaluronidase was found to be more sensitive to inhibition by a range of substances. Bovine and sheep hyaluronidase were, however, inhibited to a greater extent than scampi hyaluronidase, by human serum proteins. ©