Protein engineering of glucoamylase to increase pH optimum, substrate specificity and thermostability
US6537792B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 1999 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Jan 22, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC12N9/2428
- WIPO fieldBiotechnology
- WIPO sectorChemistry
Abstract
A fungal glucoamylase including a mutation pair Asn20Cys coupled with Ala27Cys forming a disulfide bond between the two members of the pair. The mutation provides increased thermal stability and reduced isomaltose formation to the enzyme. A fungal glucoamylase including a 311-314Loop mutation wherein reduced isomaltose formation is provided by the mutation is also provided. A fungal glucoamylase including a mutation Ser411Ala wherein increased pH optimum and reduced isomaltose formation is provided by the mutation is also provided. Combinations of the mutations in engineered glucoamylases are also provided as are combinations with other glucoamylase mutations that provide increased thermal stability, increased pH optimum and reduced isomaltose froamtion for cumulative improvements in the engineered glucoamylases. Also provided is a fungal glucoamylase including a mutation of Ser30Pro coupled with at least two stabilizing mutations forming a disulfide bond between the two stabilizing members. A fungal glucoamylase including a Ser30Pro/Gly137Ala/311-314 Loop is provided. A fungal glucoamylase including a mutation Ser30Pro/Glu137Ala/Ser411Ala is also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.