摘要
用Ｂｏｌｔｏｎ－Ｈｕｎｔｅｒ试剂联结法标记胆囊收缩素（ＣＣＫ８），得１２５Ｉ－ＢＨ－ＣＣＫ８，其比放射性为３．４ＴＢｑ／ｍｍｏｌ，放射化学纯度大于９６％。取其与自制的大鼠大脑皮质细胞膜进行受体放射分析，发现标记配体与大鼠大脑皮质ＣＣＫ受体的结合具有温度和时间依赖性，可饱和性，可逆性及特异性。经Ｓｃａｔｃｈａｒｄ分析获大鼠大脑皮质细胞膜ＣＣＫ受体Ｋｄ值为１．０９８ｎｍｏｌ／Ｌ，Ｂｍａｘ为１９７．５ｆｍｏｌ／ｍｇ蛋白。
A radioligand binding assay system for determining the
characterization of CCK receptor is presented. Using BoltonHunter reagent, we prepared a
biologically active, specific125IBHCCK8. The iodination mixture was then transferred to a
column of Sephadex G25 and examined by silica thin layer chromatography. Its specific
activity and radiochemical purity were 3.4 TBq/mmol and 96% respectively. Binding
of125IBHCCK8 to the membrane of rat cerebral cortex was rapid, reversible, timetemperature
dependent, saturable and specific. The labeled CCK was shown to have biological activity as
measured by the CCK receptor radioassay. Under our laboratorial conditions, the CCK binding
required an hour to reach equilibrium at 4. We chose polyethylene glycol 6 000 and globulin
protein for the separation of B and F. Scatchard plot of CCK binding was linear with a Kd value
of 1.098nmol/L and Bmax of 197.5 fmol/mg protein.The results of this study support the
standpoint that CCK may function as a regulatory peptide in Receptor radioassaybrain and
hence may be of use for clarifying the CCK receptor's function in central nervous system.
出处
《华西医科大学学报》
CAS
CSCD
1999年第2期214-216,221,共4页
Journal of West China University of Medical Sciences
