The present invention relates to a preparation process of recombinant human parathyroid hormone PTH(1-34). The process constitutes a new engineering strain to result in high expression amount, simple purifying course and low cost.The present invention adopts colibacillus degenerate codon modifying sequence corresponding cDNA, the basic sequence is L-V-P-R-PTH(1-34), where L-V-P-R is the enzyme incision site of thrombin. To the end of the nucleotides sequence, colibacillus terminator codon TAA is added; and in order to clone easily to the 5'-terminal enzyme incision site of EcoR I is added, and to the 3'-terminal, enzyme incision site of Sal I is added. High-purity recombinant huamn parathyroid hormone PTH(1-34) is obtained through fermentation of the engineering bacteria, occlusion body extraction, diluting renaturation, thrombase incision, anionic exchange chromatography and other steps. |