title: Analysis of extracellular proteins of two Perkinsus spp. isolated from the softshell clam Mya arenaria in vitro.
abstract: Biochemical characterization of the extracellular proteins (ECP) of two softshell clam Perkinsus spp. cloned isolates, Perkinsus chesapeaki isolate G-117 and Perkinsus marinus H-49, was performed and compared to that of the oyster-derived P. marinus isolate P-1. G-117 and H-49 demonstrated distinct differences in enzyme activities; however, all three isolates shared common bands. Substrate-impregnated gels showed H-49 to possess proteolytic activities while G-117 did not. Inhibition studies revealed that H-49 ECP contain serine proteases similar to those described for P-1. The G-117 ECP lacked proteolytic activity but showed a higher production of lipolytic enzymes than H-49 or P-1. Optimal in vitro growth temperatures for the two clam isolates were generally lower than those for P-1. G-117 showed faster growth at lower salinities than either H-49 or P-1. Clam Perkinsus spp. isolates appear to be better adapted to lower salinities and temperatures than the P. murinus isolate of the eastern oyster.
authors.affiliation: NOAA, National Ocean Service, Center for Coastal Environmental Health and Biomolecular Research, Oxford, MD 21654, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: McLaughlin
authors.forename: E E
authors.initials: EE
authors.lastname: Elsayed
authors.forename: M
authors.initials: M
authors.lastname: Faisal
mesh_terms: D000818:Animals; D016782:Apicomplexa / Q000737:chemistry / Q000201:enzymology / Q000302:isolation & purification / Q000502:physiology*; D049872:Bivalvia / Q000378:metabolism / Q000469:parasitology*; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D015800:Protozoan Proteins / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology; D013696:Temperature
chemical_list: D011480:Protease Inhibitors; D015800:Protozoan Proteins; D012965:Sodium Chloride; D010450:Endopeptidases