pyruvate kinase M-type (PKM)
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Function
- glycolytic enzyme that catalyzes the transfer of a phosphoryl group from phosphoenolpyruvate (PEP) to ADP, generating ATP
- isoform M2 is allosterically activated by D-fructose 1,6-biphosphate (FBP)
- carbohydrate degradation; glycolysis pyruvate from D-glyceraldehyde 3-phosphate: step 5/5
- phosphorylated upon DNA damage, probably by ATM or ATR
ATP + pyruvate <--> ADP + phosphoenolpyruvate
- KM=2.7 mM for phosphoenolpyruvate#
- KM=0.17 mM for phosphoenolpyruvate (in the presence of 2mM FBP)
- KM=0.34 mM for ADP
- KM=0.24 mM for ADP (in the presence of 2mM FBP)
# at pH=8 & 32 degrees celsius
inhibited by oxalate
Structure
homotetramer belongs to the pyruvate kinase family
Alternative splicing
named isoforms=2
Expression
- early fetal tissues as well as in most cancer cells
Genetics
- M1 & M2 isoforms from same gene, by alternative splicing
Notes
- 4 isozymes of pyruvate kinase in mammals: L, R, M1 & M2
- L type is major isozyme in the liver
- R is found in red cells
- M1 is the main form in muscle, heart & brain
- M2 is found in early fetal tissues as well as in most cancer cells
More general terms
More specific terms
References
- ↑ UniProt http://www.uniprot.org/uniprot/P14786.html
- ↑ Wikipedia; Note: pyruvate kinase entry http://en.wikipedia.org/wiki/pyruvate_kinase
- ↑ Stryer Biochemistry WH Freeman & Co, New York,1988 pg 362
- ↑ Wikipedia; Note: pyruvate kinase entry http://en.wikipedia.org/wiki/pyruvate_kinase