title: Identification of an AII(3-8) [AIV] binding site in guinea pig hippocampus.
abstract: A unique angiotensin binding site specific for the hexapeptide, AII(3-8), has been identified in guinea pig hippocampus. This binding site, which is present in the pyramidal cell layer of CA1, CA2, CA3 of the hippocampus and dentate gyrus, binds AII(3-8) with high affinity (KD = 1.29 +/- 0.18 nM) in a saturable manner (Bmax = 449 +/- 62 fmol/mg protein). The N-terminal structure of the binding ligand is paramount in determining the binding affinity. The C-terminal requirements seem less stringent as evidenced by the binding affinity of AII(3-7) (KD = 20.9 +/- 2.1 nM). Neither AII, AIII,Sar1, Ile8-AII, Dup 753 nor CGP42112A appear to bind, indicating that this binding site is neither the AT1 nor AT2 sites described for AII/AIII. Autoradiographic analysis of hippocampus binding confirms the inability of Sar1,Ile8-AII to compete for [125I]AII(3-8) binding. Conversely AII(3-8) was unable to displace [125I]Sar1,Ile8-AII binding.
authors.affiliation: Department of Veterinary and Comparative Anatomy, Washington State University, Pullman 99164-6520.
authors.forename: J W
authors.initials: JW
authors.lastname: Harding
authors.forename: V I
authors.initials: VI
authors.lastname: Cook
authors.forename: A V
authors.initials: AV
authors.lastname: Miller-Wing
authors.forename: J M
authors.initials: JM
authors.lastname: Hanesworth
authors.forename: M F
authors.initials: MF
authors.lastname: Sardinia
authors.forename: K L
authors.initials: KL
authors.lastname: Hall
authors.forename: J W
authors.initials: JW
authors.lastname: Stobb
authors.forename: G N
authors.initials: GN
authors.lastname: Swanson
authors.forename: J K
authors.initials: JK
authors.lastname: Coleman
authors.forename: J W
authors.initials: JW
authors.lastname: Wright
mesh_terms: D000804:Angiotensin II / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive; D006168:Guinea Pigs; D006624:Hippocampus / Q000378:metabolism*; D007457:Iodine Radioisotopes; D007700:Kinetics; D008297:Male; D011712:Pyramidal Tracts / Q000378:metabolism; D011945:Receptors, Angiotensin / Q000032:analysis / Q000378:metabolism*
chemical_list: D007457:Iodine Radioisotopes; D011945:Receptors, Angiotensin; D000804:Angiotensin II; C012877:angiotensin II, des-Asp(1)-des-Arg(2)-Ile(5)-