| 摘要 |
Stereoselective production of cyclic L-aminoacids (I) involves conversion of an L-diaminoacid (II) in presence of an ornithine cyclodeaminase (OCDA) (or a homologous peptide) in an aqueous medium, followed by recovery of (I) having an enantiomeric excess (e.e.) of at least 80%. Stereoselective production of cyclic L-aminoacids of formula (I) (or their salts or derivatives) involves conversion of an L-diaminoacid of formula (II) (or its salts or derivatives, optionally as a mixture with corresponding D-diaminoacid compounds) in presence of an ornithine cyclodeaminase (OCDA) (or a homologous peptide) in an aqueous medium, followed by recovery of (I) having an enantiomeric excess (e.e.) of at least 80%. Provided that: (1) If the enzyme is a native OCDA from Clostridium or Agrobacterium, then (II) is other than L-ornithine; and (2) if (II) is L-lysine, then reaction is not carried out using living, non-recombinant microorganisms of genus Alcaligenes, Providencia, Proteus, Bacillus, Agrobacterium, Morganella or Planococcus. R1 = H or 1-6C alkyl; X = saturated, linear or branched 2-9C (preferably 2-4C) hydrocarbon chain (optionally interrupted by one or more of O, S and NR2; and optionally substituted by one or more of OH, NH2 or halo); R2 = H or 1-4C alkyl. Independent claims are included for three polynucleotide sequences encoding recominbant enzymes for use in the production of cyclic L-aminoacids. (1) 1097 bases; the pipA asterisk gene sequence; (2) 1061 bases; the rapL asterisk gene sequence; and (3) 1061 bases; the rapL asterisk asterisk gene sequence. The sequences are fully defined in the specification. |
