title: Receptor binding activity and cytosolic free calcium response by synthetic endothelin analogs in cultured rat vascular smooth muscle cells.
abstract: Using a variety of synthetic analogs of porcine endothelin (pET), we have studied the effects of these analogs on receptor binding activity and cytosolic free Ca2+ concentrations ([Ca2+]i) in cultured rat vascular smooth muscle cells (VSMC). Removal of C-terminal Trp21 residue, truncated derivatives pET(1-15) and (16-21), substitution of disulfide bond, Cys(3-11) or Cys(1-15), by Cys (Acm), all resulted in a complete loss of receptor binding activity and [Ca2+]i response, while N-terminal elongation of Lys-Arg residues, but not oxidation of Met7 residue, decreased receptor binding activity and [Ca2+]i response. [Cys1-15,Cys3-11]pET was far more potent than [Cys1-11,Cys3-15]pET in receptor binding and [Ca2+]i response. These data indicate that the C-terminal Trp21 as well as the proper double cyclic structure formed by the intramolecular disulfide bonds of the pET molecule are essential for receptor binding and subsequent [Ca2+]i increase in rat VSMC.
authors.affiliation: Department of Medicine, Tokyo Medical and Dental University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hirata
authors.forename: H
authors.initials: H
authors.lastname: Yoshimi
authors.forename: T
authors.initials: T
authors.lastname: Emori
authors.forename: M
authors.initials: M
authors.lastname: Shichiri
authors.forename: F
authors.initials: F
authors.lastname: Marumo
authors.forename: T X
authors.initials: TX
authors.lastname: Watanabe
authors.forename: S
authors.initials: S
authors.lastname: Kumagaye
authors.forename: K
authors.initials: K
authors.lastname: Nakajima
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: S
authors.initials: S
authors.lastname: Sakakibara
mesh_terms: D000818:Animals; D001011:Aorta; D001667:Binding, Competitive; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D016232:Endothelins; D007457:Iodine Radioisotopes; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017466:Receptors, Endothelin; D013329:Structure-Activity Relationship; D013552:Swine
chemical_list: D016232:Endothelins; D007457:Iodine Radioisotopes; D010455:Peptides; D011956:Receptors, Cell Surface; D017466:Receptors, Endothelin; D002118:Calcium