Characterization of Invertase from Saccharomyces cerevisiae


It is known that the yeast enzyme invertase hydrolyzes sucrose to form glucose (an alpha-glucoside) and fructose (a beta-fructofuranoside).  In this study, invertase was studied to determine the substrate specificity required by the enzyme, and compounds were tested as potential inhibitors of the enzyme.

Invertase’s substrate specificity was tested by examining whether it hydrolyzes other alpha-glucosides or other beta-fructofuranosides, and results indicate invertase is a beta-fructofuranosidase and not an alpha-glucosidase.  The alpha-glucosides tested were maltose and cellobiose, and neither showed any significant hydrolysis by invertase.  The beta-fructofuranosides chosen were raffinose and melezitose, and both indicated significant evidence of hydrolysis.

Two prospective compounds were chosen as potential inhibitors of invertase: fructose, with the possibility of behaving as a feedback inhibitor; and sucralose, a sucrose analog, as a possible competitive inhibitor.  Results for fructose were inconclusive, and the results for sucralose show that it may be an uncompetitive inhibitor.


  1. Abstract
  2. Introduction
  3. Methods
  4. Results
  5. Conclusions
  6. References

Experiment Outline

Candidate Oligosaccharides Examined as Possible Substrates

Experiment 1

Activity of Invertase with Beta-Fructofuranosides
by Mike Gleason
[Formal Write-Up] [Standard Curves] [Lineweaver-Burk Plot] [Full Spreadsheet]

Experiment 2

Activity of Invertase with Alpha-Glucosides
by Mike Gleason
[Formal Write-Up]

Experiment 3

Inhibition of Invertase
by Mike Gleason
[Formal Write-Up] [Lineweaver-Burk Plot] [Full Spreadsheet]

Experiment 4

Stability of Various Invertase Preparations
by Mike Gleason
[Formal Write-Up] [Comparison Graph] [Full Spreadsheet]
Performed, but not included in the final results.  An error occurred midway through the experiment and there aren't enough data points to reach any meaningful conclusions.

Experiment 5

Activity of Invertase with Varied pH
by Mike Gleason
[Formal Write-Up] [Data Sheet]
Written up, but not performed due to time constraints.

Experiment 6

Characterization of Invertase with SDS-PAGE
by Magally Castillo
[Formal Write-Up] [Gel Photo]
Warning: the experiment write-up and results have numerous problems

Experiment 7

Characterization of Invertase with Agarose Gel Electrophoresis
by Magally Castillo
[Write-Up] [Gel Photo]
Warning: the experiment write-up and results have numerous problems

© 2004 Mike Gleason .  All Rights Reserved.