Mussap C J, Burcher E
Department of Biological Sciences, Deakin University, Victoria, Australia.
Peptides. 1990 Jul-Aug;11(4):827-36. doi: 10.1016/0196-9781(90)90200-o.
The cyclic tachykinin scyliorhinin II (SCYII) has high affinity for the [neurokinin B (NKB)-preferring] NK3 receptor. SCYII was iodinated using [125I]-Bolton-Hunter reagent and the product BHSCYII purified using reverse phase HPLC. In rat brain membranes, binding of BHSCYII and of the relatively unselective radioligand [125I]-Bolton-Hunter eledoisin (BHELE) was saturable, reversible and to an NK3 site. In competition studies, the rank order of potency in inhibiting binding of BHSCYII and BHELE was: SCYII greater than or equal to [MePhe7]-NKB approximately senktide greater than NKB greater than or equal to kassinin greater than or equal to eledoisin greater than [Pro7]-NKB greater than neurokinin A greater than neuropeptide K greater than or equal to substance P greater than [Sar9, Met(O2)11]-substance P. In "cold" saturation experiments, binding of BHELE occurred to a single class of high affinity sites (KD, 18.6 +/- 0.91 nM). Binding of BHSCYII was of greater affinity than for BHELE and could be resolved into a high (KD, 1.33 +/- 0.98 nM; 27% of sites) and low affinity (KD, 9.84 +/- 2.75; 73% of sites) component. The total number of binding sites was similar for both radioligands (BHSCYII, 8.27 +/- 0.98; BHELE, 7.94 +/- 0.32 fmol/mg wet weight). In vitro autoradiography in slide-mounted sections of rat brain showed identical binding patterns for both radioligands (100 pM), with dense binding localized predominantly to the cortex, Ammon's horn field 1, premammillary nuclei and interpeduncular nucleus.(ABSTRACT TRUNCATED AT 250 WORDS)
环速激肽鲨肌素II（SCYII）对[偏好神经激肽B（NKB）的]NK3受体具有高亲和力。使用[125I]-博尔顿-亨特试剂对SCYII进行碘化，并使用反相高效液相色谱法纯化产物BHSCYII。在大鼠脑膜中，BHSCYII和相对非选择性放射性配体[125I]-博尔顿-亨特伊索蛙肽（BHELE）的结合是可饱和的、可逆的，且作用于NK3位点。在竞争研究中，抑制BHSCYII和BHELE结合的效力排序为：SCYII≥[MePhe7]-NKB≈森克肽＞NKB≥卡辛宁≥伊索蛙肽＞[Pro7]-NKB＞神经激肽A＞神经肽K≥P物质≥[Sar9, Met(O2)11]-P物质。在“冷”饱和实验中，BHELE与一类高亲和力位点结合（解离常数KD为18.6±0.91 nM）。BHSCYII的结合亲和力高于BHELE，可解析为高亲和力（KD为1.33±0.98 nM；占位点的百分之27）和低亲和力（KD为9.84±2.75；占位点的百分之73）成分。两种放射性配体的结合位点总数相似（BHSCYII为8.27±0.98；BHELE为7.94±0.32 fmol/mg湿重）。在大鼠脑载玻片切片上进行的体外放射自显影显示，两种放射性配体（100 pM）具有相同的结合模式，密集结合主要定位于皮质、海马1区、乳头前核和脚间核。（摘要截断于250字）
