title: Release of hyaluronidase during in vitro development of Ascaris suum from the third to fourth larval stage.
abstract: An enzyme that degraded glycosaminoglycan hyaluronic acid was released during in vitro development of Ascaris suum L3 to L4. The enzyme did not hydrolyze glycosaminoglycan chondroitin sulfate A. One molecular form of hyaluronidase was detected, with a molecular weight estimated at 47.8 +/- 8.6 kDa by sucrose density gradient centrifugation and at 55.0 +/- 1.3 kDa by substrate SDS-PAGE zymography. Activity of the enzyme was optimal between pH 5.0 and 6.0, and was present at neutral pH. Hyaluronidase activity was not affected by 5 mM concentrations of cupric sulfate, zinc chloride, calcium chloride, manganese chloride or EDTA. In addition, NaCl had no effect on enzyme activity at concentrations of 0.2-1.0 M. The highest level of hyaluronidase was present in culture fluid collected between days 4 and 6 of in vitro culture, and this period corresponded with that of the highest rate of increase in the percentage of L4. The presence or absence of hyaluronic acid plays a key role in basic developmental processes of vertebrates and is regulated, in part, by hyaluronidases. Developmental processes occurring during the transition of A. suum L3 to L4 may likewise depend on hyaluronidase. In addition, the infection process of a number of organisms, including some nematodes, depends on hyaluronidase. A. suum may likewise utilize hyaluronidase to facilitate larval migration within the host.
authors.affiliation: Parasite Biology, Epidemiology, and Systematics Laboratory, Animal and Natural Resources Institute, US Department of Agriculture, Beltsville, MD 20705, USA. mrhoads@anri.barc.usda.gov
authors.forename: M L
authors.initials: ML
authors.lastname: Rhoads
authors.forename: R H
authors.initials: RH
authors.lastname: Fetterer
authors.forename: J F
authors.initials: JF
authors.lastname: Urban
mesh_terms: D000818:Animals; D017165:Ascaris suum / Q000201:enzymology* / Q000254:growth & development*; D003470:Culture Media; D006821:Hyaluronoglucosaminidase / Q000378:metabolism*; D007814:Larva / Q000201:enzymology / Q000254:growth & development
chemical_list: D003470:Culture Media; D006821:Hyaluronoglucosaminidase