title: [Synthesis of hirudin variant 1 (HV1) gene and primary study of expression in yeast].
abstract: OBJECTIVE
  Hirudin is an extremely efficient and specific thrombin inhibitor. It is clinically used to prevent the formation of thrombus. In this research the hirudin gene was put into yeast system for expression to evaluate the feasibility of artificially synthesized gene expressed in eukaryotic system and study the factor affecting expression level.
  
  
  METHODS
  According to the amino acid sequence of hirudin variant 1 (HV1), the genetic code saccharomyces cerevisiae was used to design and synthesize the HV1 gene. Amplified by PCR, it was inserted into cloning vector pBS-SK(+) and sequenced. Ligation with the signal peptide gene of yeast alpha factor the correct HV1 gene was inserted into yeast expression vector pYC-DE. The recombinant plasmid was transformed into the cell of S. cerevisiae BJ1990 to carry out the primary expression experiment.
  
  
  RESULTS
  In cultured supernatant of screened positive clone the hirudin activity was detected to be 30 ATU/ml. The expression level was higher than HV2 in yeast and HV1 in prokaryotic system. The N terminal amino acid sequence completely matches with natural hirudin.
  
  
  CONCLUSIONS
  It was proved by this study that the synthesized hirudin gene had been expressed in yeast successfully. This result showed that it was a better way to carry out the expression in yeast using synthesized HV1 gene and a stronger promoter.
authors.affiliation: Institute of Medical Biology, CAMS and PUMC, Kunming 650107.
authors.forename: Y
authors.initials: Y
authors.lastname: Zan
authors.forename: M
authors.initials: M
authors.lastname: Sun
authors.forename: R
authors.initials: R
authors.lastname: Guo
authors.forename: C
authors.initials: C
authors.lastname: Dai
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000235:genetics; D005813:Genes, Synthetic; D006629:Hirudins / Q000096:biosynthesis* / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism
chemical_list: D006629:Hirudins; D004247:DNA