豚鼠海马体中AII(3 - 8)[禽流感病毒]结合位点的鉴定。

Identification of an AII(3-8) [AIV] binding site in guinea pig hippocampus.

作者信息

Harding J W, Cook V I, Miller-Wing A V, Hanesworth J M, Sardinia M F, Hall K L, Stobb J W, Swanson G N, Coleman J K, Wright J W

机构信息

Department of Veterinary and Comparative Anatomy, Washington State University, Pullman 99164-6520.

出版信息

Brain Res. 1992 Jun 26;583(1-2):340-3. doi: 10.1016/s0006-8993(10)80047-2.

DOI:10.1016/s0006-8993(10)80047-2

PMID:1504842

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.

摘要

在豚鼠海马体中已鉴定出一种对六肽AII(3 - 8)具有特异性的独特血管紧张素结合位点。该结合位点存在于海马体CA1、CA2、CA3和齿状回的锥体细胞层，以可饱和的方式（Bmax = 449 ± 62 fmol/mg蛋白质）与AII(3 - 8)高亲和力结合（KD = 1.29 ± 0.18 nM）。结合配体的N端结构对于确定结合亲和力至关重要。C端要求似乎不那么严格，AII(3 - 7)的结合亲和力（KD = 20.9 ± 2.1 nM）证明了这一点。AII、AIII、Sar1、Ile8 - AII、Dup 753和CGP42112A似乎均不结合，表明该结合位点既不是针对AII/AIII所描述的AT1位点也不是AT2位点。海马体结合的放射自显影分析证实了Sar1、Ile8 - AII无法竞争[125I]AII(3 - 8)的结合。相反，AII(3 - 8)无法取代[125I]Sar1、Ile8 - AII的结合。