• USA Home
  • P5381 - Phosphoglucose Isomerase from baker's yeast (S. cerevisiae)

P5381 Sigma

Phosphoglucose Isomerase from baker's yeast (S. cerevisiae)

Type III, ammonium sulfate suspension, ≥400 units/mg protein (biuret)

Synonym: D-Glucose-6-phosphate ketol-isomerase, PGI, Phosphosaccharomutase



Unit Definition

One unit will convert 1.0 μmole of D-fructose 6-phosphate to D-glucose 6-phosphate per min at pH 7.4 at 25 °C.

Physical form

Crystalline suspension in 2.6 M (NH4)2SO4 containing 0.1 mM magnesium acetate, pH 7.0


Phosphoglucose Isomerase is an enzyme crucial for the interconversion of D-glucose 6-phosphate and D-fructose 6-phosphate. PGI is responsible for the second step of glycolysis and is involved in glucogenesis. It is highly conserved in bacteria and eukaryotes. It is used in sugar assays to convert fructose to glucose.

The enzyme has been used to convert fructose to glucose while evaluating fructose content in kudzu roots.

Biochem/physiol Actions

Phosphoglucose Isomerase fuctions as an isomerase, neuroleukin, autocrine motility factor, and a differentiation and maturation mediator. The protein has a molecular weight of approximately 119,500 ± 600 and is composed of four subunits that are nearly identical.

Price and Availability

Expore Enzymes, Proteins & Cofactors

Celebrate Pi Day!
Safety & Documentation

Safety Information

Personal Protective Equipment 
NONH for all modes of transport
WGK Germany 

Frequently Asked Questions

Which document(s) contains shelf-life or expiration date information for a given product?
If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis. These documents are located on the product detail page under Useful Links & Tools. Click on the following link to search for a Certificate of Analysis. Please click the following link to see the details on our Product Dating Information.
How do I get lot-specific information or a Certificate of Analysis?
A Certificate of Analysis is available by lot number and can be obtained through our Advanced Search Option: http://www.sigmaaldrich.com/catalog/AdvancedSearchPage.do
How do I find price and availability?
There are several ways to find pricing and availability for our products.  Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers. 
What is the Department of Transportation shipping information for this product?
Transportation information can be found in Section 14 of the product's (M)SDS. To access the shipping information for this material, use the link on the product detail page for the product, or search here. 
My question is not addressed here, how can I contact Technical Service for assistance?
Use the option to the right to "Ask a Question" by email of a Technical Service Scientist.
What is the substrate for Phosphoglucose Isomerase from baker's yeast (e.g., Product No. P5381)?
The substrate for PGI is D-fructose-6-phosphate, according to our Enzyme Assay procedure. Here is the link to that document:  http://www.sigmaaldrich.com/etc/medialib/docs/Sigma/Enzyme_Assay/p5381enz.Par.0001.File.tmp/p5381enz.pdf
What is the typical protein concentration for Product No. P5381 (PGI)?
The protein concentration of Product No. P5381 (PGI) can vary from lot-to-lot. It is typically in the range of 5-20 mg protein per mL. The lot-specific concentration will be given on the certificate of analysis.
What is the pH optimum of Phosphoglucose Isomerase from baker's yeast (e.g., Product No. P5381)?
The pH optimum for yeast PGI (Product No. P5381) is 7, according to Marchand, M. et al., Eur. J. Biochem., 184, 455-464 (1989).
What is the KM value for yeast PGI (Product No. P5381) with D-Fructose-6-phosphate as substrate, and what does that mean?
KM is the concentration of substrate that leads to half-maximal velocity. The KM value for yeast PGI (Product No. P5381) with D-Fructose-6-phosphate as substrate is 0.167, according to Marchand, M. et al., Eur. J. Biochem., 184, 455-464 (1989).
Show more questions
Protocols & Articles


Ammonium Sulfate Suspensions - Technical Note

Note that for an ammonium sulfate suspension, most of the enzyme will be in solid form. It is likely that only negligible amounts of enzyme will be in the ammonium sulfate solution.
Keywords: Enzyme activity

Related Content

Enzymes & Proteins

Application Index | Enzyme Index | Substrate Index | Inhibitor Index | Cofactor Index | Lectin Index
Keywords: Cell signaling, Diagnostic, Drug discovery, Molecular biology

Peer-Reviewed Papers


Related Products

Technical Service:

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Bulk Ordering & Pricing:

Need larger quantities for your development, manufacturing or research applications?