Biochemistry II - CHEM 375

Below is a list of resources helpful in completing the lab assignments for CHEM 375. If you need help in using these resources, please contact the chemistry librarian.

If you are looking for the Turnover number, the Km value or the Specific Activity of alpha-ketoglutarate dehydrogenase, you can use one of these three sources:

• Enzyme Handbook: Located in Vanier Reference, QP 601 E5158 1990, Volume 6, this handbook contains information on alpha-ketoglutarate dehydrogenase. To use this handbook, you will need to know the EC number for your enzyme (1.2.4.2). You can usually find EC numbers by searching for your enzyme in BRENDA (an enzyme database). The Enzyme Handbook will give information on the Turnover number, Km value, and Specific Activity. In some cases, the value will be in the handbook. In other cases, the handbook will refer you to an article where you can find the value (the reference will be a number in [square brackets] which refers to an article in the reference list). All values listed in the handbook are specific to certain substrates.
  
  
  • How to cite: To cite the Enzyme Handbook, use the same format for citing the Merck Index, as indicated in the ACS Guidelines. For example, the 1990 edition of the Enzyme handbook would be cited in the following way:
    • Enzyme Handbook, 2nd ed.; Schomburg, D.;Salzmann, M., Eds.; Springer-Verlag: New York, NY, 1990; entry 1.2.4.2.
      
      
• Brenda - Enzyme database: Search for alpha-ketoglutarate dehydrogenase. Click on any link with entry number EC 1.2.4.2. In the left hand menu, look for:
  
  
  • KM Value: There will be many values. Make sure to select the value that corresponds to the organism used in your experiment. For example, if you used pig heart, select values from the organism Sus scrofa. These values were retrieved from an article. To get the citation for that article, click on the corresponding number in the "Literature" column.
  • Specific Activity (or Vmax). The Specific Activity has units of [µmol/min/mg] and is defined as Vmax/mg protein used. If you know your experimental Vmax and the amount of protein used, you can calculate your Specific Activity and compare it to the values in BRENDA. There will be different values in BRENDA depending on the Substrate or Organism used. You may have to consult the literature to retrieve the value of the Specific Activity. To do so, click on the corresponding number in the "Literature" column.
    
    
• PubMed: An alternative to BRENDA is doing a search in PubMed to find articles on the kinetic values of your enzyme. Try typing these keywords into the search box:

  specific activity properties alpha-ketoglutarate dehydrogenase pig

  Older articles usually provide kinetic data.