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US 12,584,119 B2Granted
Variant alpha-amylases having amino acid substitutions that lower the PKA of the general acid
AssigneeDanisco US Inc.
InventorsJonathan K. Lassila, Patrica Tran
Life of this patent
Estimating the term…
Abstract
Disclosed are compositions and methods relating to variant α-amylases. The variant α-amylases are useful, for example, for starch liquefaction and saccharification, cleaning starchy stains, textile desizing, baking and brewing.
Claims12
A recombinant variant of a parental Family 13 α-amylase, the variant having at least 95% amino acid sequence identity to the amino acid sequence of SEQ ID NO:
- 1 and having an amino acid mutation in an amino acid residue that lines the N-terminal side of the core β-barrel structure of the α-amylase that results in the variant having an amino acid residue that is different from the naturally occurring amino acid in the parent α-amylase, and which results in reduction of the apparent pKa value of the general acid and an increase in the activity of the variant at a pH between about 8.5 and 10.5,
- wherein the mutation is an amino acid substitution at a position selected from the group consisting of T40C, T40D, T40E, F263P, F263Y, S288D, S288K, Y364E, and Y364L corresponding to the amino acid sequence of SEQ ID NO:
- 1,
- and wherein the variant comprises a deletion of residues 181 and 182 corresponding to positions 181 and 182 in the amino acid sequence of SEQ ID NO:
- 1.
2 more elements
A method for modulating the activity of an α-amylase comprising introducing into a parental Family 13 α-amylase having at least 95% amino acid sequence identity to the amino acid sequence of SEQ ID NO:
- 1 a mutation of a residue that affects the electrostatic environment of the general acid positioned for catalysis, wherein the mutation is located at the N-terminal side of the α-amylase β-barrel, and wherein the mutation changes the electrostatic environment of the general acid in the resulting variant α-amylase,
- wherein the mutation is an amino acid substitution at a position selected from the group consisting of T40C, T40D, T40E, F263P, F263Y, S288D, S288K, Y364E, and Y364L corresponding to the amino acid sequence of SEQ ID NO:
- 1,
- and wherein the variant comprises a deletion of residues 181 and 182 corresponding to positions 181 and 182 in the amino acid sequence of SEQ ID NO:
- 1.
2 more elements
Dependencies are inferred from the claim text.