The effect of proline insertions on the thermostability of a barley alpha-glucosidase.


The thermal stability of alpha-glucosidase is important because the conversion of starch to fermentable sugars during industrial production of ethanol (e.g. brewing, fuel ethanol production) typically takes place at temperatures of 65-73 degrees C. In this study we investigate the thermostability of alpha-glucosidases from four plant species, compare their deduced amino acid sequences, and test the effect of substituting a proline for the residue present in the wild-type enzyme on the thermostability of alpha-glucosidase. The alpha-glucosidase from barley (Hordeum vulgare) was significantly less thermostable than the other three alpha-glucosidases. A comparison of the published deduced amino acid sequences of these four alpha-glucosidases revealed conserved proline residues in the three most thermostable alpha-glucosidases that were not found in the barley enzyme. Site-directed mutagenesis was done on recombinant barley alpha-glucosidase to create proteins with prolines at these conserved positions. The thermostability (T(50)) of one of these mutant enzymes, T340P, was 10 degrees C higher than the non-mutated enzyme. Study holds ProTherm entries: 13006, 13007, 13008, 13009 Extra Details: Hordeum vulgare; maltase; starch degradation

Submission Details

ID: hggeBG263

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:44 p.m.

Version: 1

Publication Details
Muslin EH;Clark SE;Henson CA,Protein Eng. (2002) The effect of proline insertions on the thermostability of a barley alpha-glucosidase. PMID:11842235
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Alpha-glucosidase Q43763 AGLU_HORVU