title: Purification and characterisation of proteins with cardiac stimulatory and haemolytic activity from the anemone Actinia tenebrosa.
abstract: Three new proteins with cardiac stimulatory and haemolytic activity, designated tenebrosins-A, -B and -C, have been purified from the Australian sea anemone Actinia tenebrosa. These proteins are basic (pI greater than or equal to 9.4), have mol. wt of about 20,000, and have very similar amino acid compositions and N-terminal amino acid sequences. None of the proteins contains cysteine or cystine residues. On isolated, spontaneously beating guinea pig atria they exhibit at 1-2 nM strong positive inotropic and slight to moderate chronotropic effects. In some cases a transient negative inotropic effect occurs prior to onset of the positive inotropic response. The proteins are also haemolytic, producing 50% haemolysis of guinea pig erythrocytes at concentrations similar to those showing positive inotropic effects.
authors.affiliation: School of Biochemistry, University of New South Wales, Kensington, Australia.
authors.forename: R S
authors.initials: RS
authors.lastname: Norton
authors.forename: G
authors.initials: G
authors.lastname: Bobek
authors.forename: J O
authors.initials: JO
authors.lastname: Ivanov
authors.forename: M
authors.initials: M
authors.lastname: Thomson
authors.forename: E
authors.initials: E
authors.lastname: Fiala-Beer
authors.forename: R L
authors.initials: RL
authors.lastname: Moritz
authors.forename: R J
authors.initials: RJ
authors.lastname: Simpson
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001315:Australia; D002316:Cardiotonic Agents; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003063:Cnidaria / Q000378:metabolism*; D003064:Cnidarian Venoms / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D006168:Guinea Pigs; D006461:Hemolysis / Q000187:drug effects*; D066298:In Vitro Techniques; D007525:Isoelectric Focusing; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008969:Molecular Sequence Data; D009200:Myocardial Contraction / Q000187:drug effects; D011506:Proteins / Q000032:analysis / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D002316:Cardiotonic Agents; D003064:Cnidarian Venoms; D011506:Proteins