胰高血糖素样肽-1在乙醇中的聚乙二醇修饰

以乙醇为溶剂,单甲氧基聚乙二醇琥珀酰亚胺碳酸酯(mPEG-SC)为修饰剂,对胰高血糖素样肽-1(GLP-1)进行了修饰反应条件的优化,同时对单修饰产物Mono-PEG-GLP-1进行分离纯化,并考察了其体外稳定性和体内活性. 得到的优化反应条件为：GLP-1浓度1 mg/mL, mPEG-SC与GLP-1摩尔比1:1, 37℃下反应24 h,该产物最高转化率达77%. 采用冷冻离心方式对Mono-PEG-GLP-1进行初步分离和浓缩,然后经反相液相色谱进一步高效纯化,纯度可达97%以上. 体外实验表明,Mono-PEG-GLP-1在血清中具有更好的稳定性及更强的抗胰蛋白酶消化能力. 体内动物实验表明,Mono-PEG-GLP-1具有更好的降血糖作用.

Modification of Glucagon-like Peptide-1 in Ethanol with Polyethylene Glycol

Glucagon-like peptide-1 (GLP-1) was modified with monomethoxy polye(ethylene glycol succinimidyl carbonate) by using ethanol as a reaction medium. The reaction conditions were investigated and optimized, and the separation procedures of product Mono-PEG-GLP-1 were developed. After that, the stability in vitro and activity in vivo of Mono-PEG-GLP-1 were investigated. The optimized reaction conditions were obtained as follows: concentration of GLP-1 1.0 mg/mL, molar ratio of PEG to GLP-1 1:1, and reaction time 24 h at 37℃. Under the optimized conditions, the yield of Mono-PEG-GLP-1 was up to 77%. The Mono-PEG-GLP-1 was separated from reaction mixture by a preliminary centrifugation under frozen temperature and successive purification by reverse phase chromatography. The purity of Mono-PEG-GLP-1 was higher than 97%, as characterized by size exclusion chromatography. The Mono-PEG-GLP-1 showed better stability in plasma, decreased proteolysis to trypsin and better activity in vivo.