title: Purification and properties of peditoxin and the structure of its prosthetic group, pedoxin, from the sea urchin Toxopneustes pileolus (Lamarck).
abstract: A protein toxin, termed peditoxin, containing an active prosthetic group was isolated and purified from the globiferous pedicellariae of the sea urchin Toxopneustes pileolus (Lamarck). The prosthetic group, called pedoxin, is a small molecular mass substance (206 daltons) with an empirical formula of C10H10N2O3 and is comprised of a heterocyclic lactone structure formed from pyridoxal and glycine. Administered subcutaneously or intramuscularly to mice in sublethal doses, pedoxin markedly reduced basal body temperature and led to sedation and anesthetic coma accompanied by muscular relaxation. At higher doses, it leads to convulsion and death (LD50 200 mg/kg). The apoprotein, a cytochrome b-like heme protein called pedin (molecular mass, 10,000 daltons) is itself not toxic, but the purified holoprotein is extremely toxic, causing anaphylaxis-like shock and death in experimental animals at low doses (LD50 70 micrograms/kg). Small amounts of the prosthetic group added to holoprotein preparations caused the toxicity to be greatly enhanced, suggesting that holoprotein preparations also contain apoprotein capable of being activated by the low molecular weight toxin. The structure of pedoxin was determined to be 3-hydroxy-2-methyl-5-methoxy-4-pyridineformyl-glycyliden ester and was confirmed by total synthesis.
authors.affiliation: Institute of Medical Science, University of Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kuwabara
mesh_terms: D000595:Amino Acid Sequence; D000777:Anesthetics / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000818:Animals; D001059:Apoproteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D003128:Coma / Q000139:chemically induced; D006993:Hypnotics and Sedatives / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D051379:Mice; D008969:Molecular Sequence Data; D011730:Pyridoxal / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology / Q000633:toxicity; D011749:Pyrogens / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D012617:Sea Urchins / Q000737:chemistry*; D017421:Sequence Analysis; D013055:Spectrophotometry, Infrared
chemical_list: D000777:Anesthetics; D001059:Apoproteins; D006993:Hypnotics and Sedatives; D011749:Pyrogens; C090086:peditoxin; C090087:pedin; C090088:pedoxin; D011730:Pyridoxal