Phosphatases and phosphodiesterases isolated from the red king crab (Paralithodes camtschatica) hepatopancreas

Five enzymes have been isolated from the hepatopancreas of the red king crab Paralithodes camtschatica by means of ion exchange and gel chromatography: two acid (AcP) and one alkaline (AlkP) phosphomonoesterases, one alkaline phosphodiesterase (AlkPI), and one acid phosphodiesterase (AcPD). The pH optimum values of these enzymes are: AlkPs and AlkPD, 7.5; AcP, 5.5; and AcPD, 5.0. The activity of AlkP and AlkPD demands Mg2+ ions. The molecular weights of the enzymes (kDa) are the following: AlkP, 80; AcPs, 80 and 82; AlkPD, 51; and AcPD, 57. The enzymes are relatively thermostable (ID 50 from 47 to 62°C). AlkP is inhibited by NaCl (IC 50 at 0.4 M). The AcP, AcPD, and AlkPD activities are tolerant of high ionic strength. [PUBLICATION ABSTRACT]