title: Toxic effects of the novel protein UpI from the sea anemone Urticina piscivora.
abstract: UpI is a basic protein, with molecular mass (approximately 28 kDa) and a pI > 9.4, isolated from the sea anemone Urticina piscivora. It is a potent cardiac stimulatory protein with the partial amino acid sequence D1ENEN5LYGPN10ENKAK15AKDLT20AGASY25LTKEA30GCTKL35QAGCT40MYQAY45N [1]. The toxic effects of UpI and the crude extract from which it was isolated have been investigated on three tumour cell lines: KB, L1210, and HEL 299 cells. UpI, however, was less potent on each cell line than the crude extract. Since previous experiments had shown extracts of U. piscivora to be haemolytic on erythrocytes of rat, guinea pig and dog, the haemolytic action of UpI was investigated. It was found to be a potent haemolysin on erythrocytes of rat, guinea pig, dog, pig and human, causing haemolysis on erythrocytes of each species tested at concentrations as low as 10(-10) M. Haemolysis was inhibited in a concentration-dependent manner by the phospholipid sphingomyelin but not cholesterol. Using scanning electron microscopy, it is now being shown that UpI produces significant structural damage to membranes of erythrocytes from rat and guinea pig. It proved to be a potent ichthyotoxin. These data suggest that sea anemone toxin not only possess different pharmacological activities but that UpI, one of the active constituents, could be responsible for the different pharmacological effects exhibited by the crude extract.
authors.affiliation: Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada.
authors.forename: E I
authors.initials: EI
authors.lastname: Cline
authors.forename: L I
authors.initials: LI
authors.lastname: Wiebe
authors.forename: J D
authors.initials: JD
authors.lastname: Young
authors.forename: J
authors.initials: J
authors.lastname: Samuel
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002784:Cholesterol / Q000494:pharmacology; D003064:Cnidarian Venoms / Q000737:chemistry / Q000633:toxicity*; D004285:Dogs; D004912:Erythrocytes / Q000187:drug effects / Q000648:ultrastructure; D005399:Fishes; D006168:Guinea Pigs; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D007624:KB Cells; D007939:Leukemia L1210 / Q000188:drug therapy; D008387:Marine Toxins / Q000737:chemistry / Q000633:toxicity*; D051379:Mice; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D051381:Rats; D013109:Sphingomyelins / Q000494:pharmacology; D013552:Swine; D014407:Tumor Cells, Cultured
chemical_list: D003064:Cnidarian Venoms; D008387:Marine Toxins; D013109:Sphingomyelins; C104394:UPI protein, sea anemone; D002784:Cholesterol