SEPARATION AND PARTIAL PURIFICATION OF CENTRAL NERVOUS SYSTEM PEPTIDES FROM LIMULUS POLYPHEMUS WITH HYPERGLYCEMIC AND CHROMATOPHOROTROPIC ACTIVITY IN CRUSTACEANS

Abstract

Crude acetic acid extracts of the Limulus CNS cause a hyperglycemic response in destalked crayfish (Orconectes immunis) which is dose-dependent. The hyperglycemic factor (LHGF) is stable to boiling, susceptible to oxidation by H2O2 inactivated by pepsin and protease, and has an apparent MW of 6400 daltons as determined on Sephadex G-50. LHGF seems to be a polypeptide. LIrF can be readily separated from another Limulus CNS factor, Limulus-Uca chromatophorotropin (LUC), by gel filtration on Sephadex G-25. Further characterization of LUC indicates that it is a peptide based on its inactivation by numerous proteolytic enzymes and an apparent MW of 1850 daltons. The similarity of these factors to known crustacean hormones is discussed.