beta-D-glucuronidase is associated with goat sperm cytoskeleton

Glycosidase activities were detected as detergent-insoluble after sequential extractions of goat sperm with Triton X-100. Seventy percent of total beta-glucuronidase activity was found in the detergent-insoluble fraction. This portion of beta-glucuronidase was resistant to extractions in the presence of 1 M KCl, chaotropic agents, colchicine, or cytochalasin B, being only partially solubilized by 3 M KCl or DNAse I treatment. The treatment with 0.1% sodium deoxycholate was effective, releasing 73% of the enzyme activity. Treating the deoxycholate extract with DNAse I resulted in a change in the elution profile of beta-glucuronidase as judged by gel filtration chromatography. A polyclonal antibody was developed against pancreatic beta-glucuronidase, and the sperm enzyme was strongly inhibited by the IgG fraction of this antibody. Western blot analysis showed that the same protein correspond to both Triton-soluble and insoluble enzyme. Results demonstrate that beta-glucuronidase is tightly bound to the Triton X-100 resistant fraction, suggesting that the enzyme is associated to sperm cytoskeleton. J. Exp. Zool. 289:146-152, 2001.