METHOD FOR PRODUCING SELENOPROTEINS

摘要

The invention describes a method for the production of recombinant selenoproteins containing an internal selenocysteine residue without the presence of other amino acids derived from the SECIS element. A first nucleic acid sequence encoding a first part of a protein to be formed is positioned upstream of an intein, with a UGA codon (which will be translated into a selenocysteine reside) located at or near the 3'-end of the first nucleic acid sequence. A SECIS sequence is then inserted into the 5'-end of the intein. A precursor protein is formed containing the first part of the protein, the intein (with the SECIS) and a second polypeptide. The intein (with SECIS) is excised from the precursor and the first and second polypeptides are joined by a peptide bond to form a protein with an internal selenocysteine residue, or alternatively, after excision of the intein, the first polypeptide is ligated to a third polypeptide (i.e. a polypeptide which was not part of the precursor protein) to form a protein with an internal selenocysteine residue. The protein does not include any amino acids derived from the SECIS apart from the selenocysteine residue.