摘要目的:用响应面法对马来酰亚胺活化相对分子质量40 000的聚乙二醇(polyethylene glycol，PEG)(MAL-PEG 40K)修饰胰高血糖素样肽1类似物(glucagon-like peptide 1 analog，GLP-1a)的反应条件进行优化。 方法:对GLP-1a浓度、GLP-1a/MAL-PEG 40K摩尔比、反应液pH值、反应温度、反应时长进行单因素试验。以前3个条件为自变量，PEG修饰率为响应值，根据中心组合试验设计原理，研究各自变量及其交互作用对PEG修饰率的影响。通过高效液相色谱法分析PEG修饰率，依据回归分析确定各反应条件的最优值。 结果:GLP-1a与MAL-PEG 40K的最佳反应条件为：GLP-1a浓度2.5 mg/ml，GLP-1a/MAL-PEG 40K摩尔比1∶1.25，反应液pH8，反应温度4 ℃，反应时长60 min。该优化条件下，GLP-1a的PEG修饰率可达91.0%。 结论:响应面法获得了GLP-1a与MAL-PEG 40K的最佳反应条件。

abstractsObjective:To optimize the reaction conditions of maleimide-activated relative molecular weight 40 000 polyethylene glycol(PEG)(MAL-PEG 40K) modified glucagon-like peptide 1 analog (GLP-1a) by response surface methodology. Methods:Single-factor tests were performed on concentration of GLP-1a, molar ratio of GLP-1a to MAL-PEG 40K, pH value of the solution, reaction temperature and reaction duration. The first 3 parameters were taken as independent variables, and the PEG modification rate was used as the response value. According to the design principle of the central combination test, the variables and their interactions were studied for influence on PEG modification rate. The PEG modification rate was analyzed by reversed-phase high performance liquid chromatography, and the optimal value of each reaction condition was determined by regression analysis. Results:The optimal PEG modification conditions of GLP-1a were GLP-1a concentration of 2.5 mg/ml, GLP-1a to MAL-PEG 40K molar ratio of 1∶1.25, solution pH of 8, reaction temperature of 4 ℃, and duration of 60 min. Under these conditions, the PEG modification rate of GLP-1a reached 91.0%. Conclusion:Using response surface methodology, the optimal reaction conditions of GLP-1a and MAL-PEG 40K are obtained.