Biocatalysts and methods for the synthesis of armodafinil
The present invention relates to non-naturally occurring polypeptides useful for preparing armodafinil, polynucleotides encoding the polypeptides, and methods of using the polypeptides. The non-naturally occurring polypeptides of the present invention are effective in carrying out biocatalytic conversion of the (i) 2-(benzhydrylsulfinyl)acetamide to (−)-2-[(R)-(diphenylmethyl)sulfinyl]acetamide (armodafinil), or (ii) benzhydryl-thioacetic acid to (R)-2-(benzhydrylsulfinyl)acetic acid, which is a pivotal intermediate in the synthesis of armodafinil, in enantiomeric excess.
1. A non-naturally occurring polynucleotide encoding a polypeptide having cyclohexanone monooxygenase (CHMO) activity wherein the amino acid sequence of the polypeptide has at least 95% sequence identity to SEQ ID NO: 136.
2. The polynucleotide of claim 1 , wherein said encoded polypeptide is capable of converting the acid substrate (1b) to compound (2b) (R-enantiomer) or its opposite enantiomer compound (S-enantiomer) with at least 2-fold improved activity relative to the wild-type polypeptide of SEQ ID NO: 2,
3. The polynucleotide of claim 2 , wherein said encoded polypeptide is capable of converting the acid substrate of compound (1b) to the R-enantiomer compound (2b) in at least 50% enantiomeric excess.
4. The polynucleotide of claim 1 , wherein said encoded polypeptide is capable of converting compound (1a) to compound (2a)
in at least 75%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99% enantiomeric excess under suitable reaction conditions.
5. The polynucleotide of claim 4 , wherein said encoded polypeptide is capable of converting compound (1a) to compound (2a) with an activity increased at least 2-fold, at least 4-fold, at least 10-fold, at least 25-fold, at least 40-fold, or at least 60-fold relative to the activity of the polypeptide of SEQ ID NO: 2 under suitable conditions.
6. The polynucleotide of claim 1 , wherein said encoded polypeptide is capable of converting compound (1b) to compound (2b)
in enantiomeric excess under suitable reaction conditions.
7. The polynucleotide of claim 6 , wherein said encoded polypeptide is capable of converting compound (1b) to compound (2b) in at least 75%, at least 85%, at least 90%, at least 95%, at least 98% or at least 99% enantiomeric excess under suitable reaction conditions.
8. The polynucleotide of claim 2 , wherein said encoded polypeptide is capable of converting compound (1b) to compound (2b) with an activity increased at least 2-fold, at least 4-fold, at least 10-fold, at least 25-fold, at least 40-fold, or at least 60-fold relative to the activity of the polypeptide of SEQ ID NO: 38 under suitable reaction conditions.
9. The polynucleotide of claim 2 , wherein said encoded polypeptide is capable of at least 90% or greater conversion of compound (1b) to compound (2b) in 24 h with a substrate loading of about 50 g/L.
10. The polynucleotide of claim 1 , wherein the polynucleotide encodes a polypeptide which comprises the amino acid sequence of SEQ ID NO: 90, 96, 98, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140 or 142.