| abstract |
The object of the present invention is to provide a preparation method of ambroxol that can easily obtain ambroxol. The technical problem can be solved by using tetraprenyl-β-curcumene cyclase in which the aspartic acid as the 4th amino acid residue of the DXDD motif is substituted with an amino acid other than aspartic acid. Cyclase: (a) Based on the DXDD motif, it has a QXXXGX(W/F) motif and a QXXXX(G/A)X(F/W/Y) motif on the N-terminal side, and a C-terminal It has a QXXXGX(F/W/Y) motif, a QXXXGXW motif, and a QXXXGX(F/W) motif on the side, and does not have a QXXXGXW motif at a position more than 170 amino acid residues away from the C-terminal side, (b) The identity to the amino acid sequence represented by SEQ ID NO: 1 or 13 is 40% or more, and (c) it uses squalene as a substrate and exhibits amberginol-producing activity. |