| 摘要 |
Disclosed are compositions and methods relating to variant maltohexaose-forming alpha-amylases. The variant alpha-amylases are useful, for example, for starch liquefaction and saccharification, for cleaning starchy stains in laundry, dishwashing, and other applications, for textile processing (e.g., desizing), in animal feed for improving digestibility, and for baking and brewing. |
| 主权项 |
1. A variant α-amylase polypeptide derived from a parental α-amylase polypeptide, comprising at least two combinable mutations at a productive amino acid positions; wherein:
(i) each combinable mutation is the substitution of an amino acid residue present in the parental α-amylase with a different amino acid residue, which improves at least one desirable property of the variant α-amylase compared to the parental α-amylase, while not significantly decreasing either expression, activity, or stability of the variant α-amylase, compared to the parental α-amylase, (ii) a productive position is an amino acid position that can be substituted with a plurality of different amino acid residues, each of which substitutions result in a variant α-amylase that meets the requirements of (i), and (iii) the combinable mutation corresponds to a mutation listed in Lists A, B, C, or D, or in Table C or D, which use SEQ ID NO: 3 for numbering wherein, the combinable mutations produce a variant amylase wherein the minimum performance indices (PI) relative to the parental amylase for (i) protein expression, (ii) activity, and (iii) detergent stability or thermostability are greater than or equal to 0.8, and the PI for any one of (i), (ii), or (iii) that is greater than or equal to 1.2, or the combinable mutations produce a variant amylase wherein the minimum performance indices (PI) relative to the parental amylase for (i) protein expression, (ii) activity, and (iii) detergent stability or thermostability are greater than or equal to 0.5, and the PI for any one of (i), (ii), or (iii) that is greater than or equal to 1.5. |
