Image of IDH (blue) from E. coli, as depicted with Jmol, shows NADP⁺ and isocitrate (both in red) bound to the enzyme. Try:

Chime Tutorials (by Rahul Karnik '00)

• IDH Tutorial #1: E. coli IDH monomer with isocitrate, NADP⁺, and Mg²⁺
• IDH Tutorial #2: E. coli IDH with NADP⁺ and Ca²⁺

Quicktime Movies of IDH

• IDH monomer with substrate, coenzyme, cofactor bound. (large format 10MB)
• IDH dimer with substrate, coenzyme, cofactor bound. (large format 10 MB)

Raw PDB Files

• IDH with a-ketoglutarate
• IDH with Mg²⁺ and isocitrate bound and
• IDH with NADP⁺ bound

The Biology Department at Davidson College has begun to develop isocitrate dehydrogenase (IDH) as a model enzyme for teaching. We presented this model system at the 1998 ASCB meeting and you can see a virtual poster summary here. Over the next year, we will be adding new protocols to this page for use in a wide range of courses, including:

Click Here for a good review of Microplate Readers (including contact information and pricing) that was published in the July 6, 1998 edition of The Scientist.

• Introductory Biology Laboratory
  • First week's lab - introduction of spectrophotometry
  • Second week's lab - introduction to IDH
  • Third week's lab - students design experiments to test hypothesis
  • Electronic suppliment - graphing with Cricket Graph (with lots of figures)
  • Electronic suppliment - instructors' notes on making solutions
    
    
• Genetics Laboratory (under construction)
  
  
• Developmental Biology Laboratory (under construction)
  
  
• Molecular Biology Semester Long Project (honors research project)
  • Lab Schedule In Context of Project
  • Molecular Biology Laboratory Schedule with Protocols Linked (now with all protocols hyperlinked)
  • Student-generated Data from Lab
    
    
• Independent Student Research - Biochemistry
  • Student Research
    • Poster 1
    • Poster 2

The idea of using IDH as a unifying enzyme was first discussed in the spring of 1996. IDH has many advantages over more traditional enzymes (e.g. tyrosinase, peroxidase, and amylase) used in laboratory courses. IDH is a enzyme that is frequently discussed in many courses, IDH requires no toxic substances to monitor the formation of one product (NADPH), and there is a great deal of information available on the enzyme and its kinetics so many variables can be manipulated by students.

Here are some other resources which demonstrate the flexibility of IDH as a model enzyme:

• Amino Acid Sequences for a few of the sequenced IDH isoforms
• Jmol (3D) image of the protein
• Yeast Protein Database on cytosolic form of IDH from Saccharomyces cerevisiae)(IDP2)
• More information about IDH
• Isolation and RNA-binding analysis of NAD⁺-isocitrate dehydrogenases from Kluyveromyces lactis and Schizosaccharomyces pombe. by Sandra D. J. Elzinga, Katinka van Oosterum, Corien Maat, Les A. Grivell, Hans van der Spek. 2000.
• Oxalomalate, a competitive inhibitor of NADP⁺-dependent isocitrate dehydrogenase, enhances lipid peroxidation-mediated oxidative damage in U937 cells. Yang JH, Park JW. Arch Biochem Biophys. 2003 Aug 1;416(1):31-7.
• Recombinant Plasmodium falciparum NADP-dependent isocitrate dehydrogenase is active and harbours a unique 26 amino acid tail. Chan M, Sim TS. Exp Parasitol. 2003. Mar-Apr;103 (3-4):120-6.

• Metabolic Pathway Maps - IDH
  • Expasy Pathway Map - lipid synthesis (Mammalian)
  • Kegg Pathway Map #1 - TCA cycle
  • Kegg Pathway Map #2 - glutathione metabolism
  • Kegg Pathway Map #3 - Reductive Carboxylate cycle in photosynthetic bacteria