title: Proteolytic activity and protease classes in the zooplankton species Calanus finmarchicus.
abstract: The temperature optimum for the general proteolytic activity in the crude extract of Calanus finmarchicus was 50 degrees C and the pH optimum was found to be 7. The use of specific protease inhibitors resulted in the identification of at least three protease classes in the crude extract of C. finmarchicus. Those classes were serine, metallo and aspartic proteases. The serine and metallo proteases were found to be dominant under neutral to alkaline conditions and the aspartic proteases were dominant under acidic conditions. The cysteine proteases, if at all present, did not seem to be active or present in any substantial amount. The data presented points towards controlling and preserving the protein content in fresh C. finmarchicus.
authors.affiliation: Norwegian Biopolymer Laboratory, Department of Biotechnology, The University of Science and Technology NTNU, Sem Saelands v 6/8, 7491 Trondheim, Norway. geir.solgaard@biotech.ntnu.no <geir.solgaard@biotech.ntnu.no>
authors.forename: Geir
authors.initials: G
authors.lastname: Solgaard
authors.forename: Inger Beate
authors.initials: IB
authors.lastname: Standal
authors.forename: Kurt I
authors.initials: KI
authors.lastname: Draget
mesh_terms: D000818:Animals; D033342:Copepoda / Q000737:chemistry / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D010447:Peptide Hydrolases / Q000032:analysis* / Q000737:chemistry; D015048:Zooplankton / Q000737:chemistry / Q000201:enzymology*
chemical_list: D010447:Peptide Hydrolases