Abstract: The invention discloses a fusion protein and its preparation method for intermediate polypeptide of Semaglutide. The invention belongs to the technical field of genetic engineering and polypeptide preparation. The fusion protein comprises a fusion peptide, a protease cleavage site and a target main molecular sequence. By optimizing the fusion peptide sequence, changing the isoelectric point and hydrophilicity of the protein, the highest expression of the fusion protein is effectively increased to 13.1 g/L. Meanwhile, the properties of fusion protein are also improved, which is conducive to the development of subsequent extraction, enzyme digestion and purification processes. The yield of intermediate polypeptide after enzyme digestion is 3.62 g/L. The production cost of Semaglutide intermediate polypeptide Arg34GLP-1(9-37) is reduced from the source, which is conducive to industrial scale-up and suitable for industrial production.

Abstract: The invention discloses a fusion protein and its preparation method for intermediate polypeptide of Semaglutide. The invention belongs to the technical field of genetic engineering and polypeptide preparation. The fusion protein comprises a fusion peptide, a protease cleavage site and a target main molecular sequence. By optimizing the fusion peptide sequence, changing the isoelectric point and hydrophilicity of the protein, the highest expression of the fusion protein is effectively increased to 13.1 g/L. Meanwhile, the properties of fusion protein are also improved, which is conducive to the development of subsequent extraction, enzyme digestion and purification processes. The yield of intermediate polypeptide after enzyme digestion is 3.62 g/L. The production cost of Semaglutide intermediate polypeptide Arg34GLP-1(9-37) is reduced from the source, which is conducive to industrial scale-up and suitable for industrial production.

Abstract: The present invention discloses novel proinsulin glargine and method for for preparing insulin glargine therefrom. A sequence of the proinsulin glargine containing SOD fusion peptide subjected to site-directed mutagenesis and “0 C peptide” is designed; recombinant Escherichia coli for expressing insulin glargine are constructed; insulin glargine fusion protein in a form of an inclusion body is expressed; and denaturation, renaturation, modification, enzyme digestion, separation and purification are carried out to obtain a mature insulin glargine active pharmaceutical ingredient. According to the present invention, the SOD fusion peptide sequence is mutated to enhance the fermentation yield of the insulin glargine by 75%; and a “0 C peptide” strategy is adopted to reduce the quality loss and miscleavage impurities in the enzyme digestion transformation. The purity of the insulin glargine active pharmaceutical ingredient prepared in the present invention is up to 99.