Objective: To study the reduction of immunogenicity of salmon calcitonin (sCT).
Methods: A new (11-17) humanized salmon calcitonin variant gene (11-17) hsCT was designed and synthesized to construct recombinant expression vector and express in E.coli G1724 with tryptophan. The fusion protein of humanized salmon calcitonin and thioredoxin (Trx-hsCT) obtained from the bacterial by means of osmotic pressure; The bioactivity of Trx-hsCT was estimated by serum calcium reduction method in rat; The quantitative Western blot analysis was used for detecting the immunogenicity of hsCT.
Results: Recombinant expressing vector pTrxFus-hsCT was expressed in high level and soluble in E.coli G1724, reaching 46% of total bacterial protein and obtaining the fusion protein of 90% purity; Special bioactivity of hsCT was preserved that of half pre-sCT and its immunogenicity reduced over 50% that of pre-sCT.
Conclusion: Obtain a new humanized salmon calcitonin variant(11-17) hsCT which maintains a rather high bioactivity over pre-sCT and decreases distinctly its immunogenicity.