title: Purification and characterization of an antibacterial and antineoplastic protein secretion of a sea hare, Aplysia juliana.
abstract: The fetid secretion of a sea hare, Aplysia juliana, was lethal to crabs and also inhibited the growth of bacteria. When the secretion was partitioned between water and n-hexane, only the n-hexane layer, which had a nauseating odor, was lethal to crabs. The water-soluble fraction showed strong antibacterial activity and inhibited the growth of both Gram-positive and Gram-negative bacteria. Antibacterial activity of the water-soluble fraction was destroyed by heating at 50 degrees C for 15 min, but was resistant to treatment with proteolytic enzymes. The active principle, named julianin-S, was purified by gel filtration and ion exchange chromatography. The purified specimen gave a single protein showing a mol. wt of approximately 67,000, as determined by gel filtration. Julianin-S inhibited the growth of Bacillus subtilis by 50% at a concentration of 70 ng protein/ml. It was also cytotoxic to murine tumor cells and inhibited in vitro growth of L1210 cells by 50% at a concentration of 8 ng protein/ml.
authors.affiliation: School of Fisheries Sciences, Kitasato University, Iwate, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kamiya
authors.forename: K
authors.initials: K
authors.lastname: Muramoto
authors.forename: R
authors.initials: R
authors.lastname: Goto
authors.forename: M
authors.initials: M
authors.lastname: Sakai
authors.forename: Y
authors.initials: Y
authors.lastname: Endo
authors.forename: M
authors.initials: M
authors.lastname: Yamazaki
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification*; D000970:Antineoplastic Agents / Q000302:isolation & purification*; D001048:Aplysia / Q000032:analysis*; D001419:Bacteria / Q000187:drug effects; D001681:Biological Assay; D006023:Glycoproteins / Q000302:isolation & purification* / Q000494:pharmacology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D010447:Peptide Hydrolases; D014357:Trypsin
chemical_list: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D006023:Glycoproteins; D010447:Peptide Hydrolases; D014357:Trypsin