目的:改良一种基于胞内cAMP浓度变化,用于融合蛋白GGH生物学活性测定的方法。方法:根据融合蛋白GGH是GLP-1类似物,能促进胰岛B细胞增殖,产生胞内第二信使cAMP的原理,利用酶联免疫法测定胞内cAMP的含量。结果:Exenatide或融合蛋白GGH刺激大鼠B胰岛素瘤细胞RINmSf后,选用100nmol/L1BMX作为cAMP保护剂,用DPBS为药物稀释剂,采用液氮-100℃反复冻融2次裂解细胞,最后用酶联免疫法可稳定的测定上清液中cAMP含量。结论:成功改良了融合蛋白GGH体外高通量生物学活性测定方法。运用此方法可快速鉴定融合蛋白GGH及其它GLP,l类似物的生物活性。
Objective: To improve a method to determine bioactivity of the fusion protein GGH based on the intraeellular cAMP level. Methods: According to GGH is the analog of GLP-1 which can promote islet 13 cells to produce second messenger cAMP, detecting intracellular cAMP levels by enzyme-linked immunosorbent assay (ELISA) can be used to characterize GGH biological activity. Results: Exenatide or GGH was used to stimulate rat insulinoma cell line RIN mSf to produce cAMP. The optimal cAMP protective agent and drug diluent were 100nmol/L IBMX and DPBS. We found that freezing and thawing cells in liquid nitrogen 2 times led to maximum and stable production of cAMP in the supernatant measured by ELISA. Conclusion: An in vitro high-throughput screening method for detecting the bioactivities of the fusion protein GGH was successfully modified. Using this method, the biological activity of GGH and GLP-1 analogs can be rapidly identified.