Purification and Properties of β‐Glucuronidase from the Muscle of Bombay Duck (Harpodon Nehereus)

摘要

ABSTRACTBombay duck muscle β‐glucuronidase purified 4200‐fold had molecular weight of 160,000 as estimated by gel filtration on Sephadex G‐200. The glycoprotein enzyme exhibited dimeric structure on SDS‐PAGE and had a pI of 5.0. The enzyme was optimally active at pH 5.2 when phenolphthalein β‐D‐glucuronide was used as the substrate while with p‐nitrophenyl glucuronide the pH optimum was 4.6. Saccharo‐1,4‐lactone was a potent competitive inhibitor of the enzyme. Heavy metalic ions such as Hg2+, Cd2+and Ag+also proved to be inhibitory to the enzyme. Radiation inactivation of the enzyme could be protected in the presence of mercaptoethanol. Sodium chloride activated the enzyme while sodium tripolypho