title: [Construction and expression of a new humanized salmon calcitonin variant].
abstract: 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.
  
  
  CONCLUSIONS
  Obtain a new humanized salmon calcitonin variant(11-17) hsCT which maintains a rather high bioactivity over pre-sCT and decreases distinctly its immunogenicity.
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, CAMS and PUMC, Beijing 100005, China.
authors.forename: S J
authors.initials: SJ
authors.lastname: Liu
authors.forename: S S
authors.initials: SS
authors.lastname: Chen
authors.forename: X
authors.initials: X
authors.lastname: Di
authors.forename: A Q
authors.initials: AQ
authors.lastname: Xiong
authors.forename: Y H
authors.initials: YH
authors.lastname: Zhang
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002116:Calcitonin / Q000096:biosynthesis* / Q000235:genetics* / Q000276:immunology; D004926:Escherichia coli / Q000235:genetics; D014644:Genetic Variation; D005822:Genetic Vectors; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology
chemical_list: D011993:Recombinant Fusion Proteins; C028815:salmon calcitonin; D002116:Calcitonin