AA metabolism 2 Flashcards
Important coenzymes for AA metabolism
- PLP (from B6) it can donate and remove amino groups involved in degredation of all AAs except (Threonine, lysine, proline, hydroxy proline)
- BH4 (tetrahydrobiopterin)- coenzyme for hydroxylation rxn of ring AAs. You can make BH4 to BH2 via dihydrobiopterin Reductase
- THF (FH4) tetrahydrofolate- coenzyme that transfers one carbon units. Folate is the most oxidized form, and THF is the most reduced form
One Carbon metabolism
Transamination (uses PLP)
One-C transfer (uses THF, BH4)
One carbon metabolism: one carbons are too volitile, so they need to be attached to something to be processed (folate)
Folates serve as a donor of 1-C units in one of three oxidation states: (formyl, methylene, methyl THFs). Folates hold the one carbon units given from serine, methionine, Glycine, and histidine
One carbons are transferred by reactions involving TH4, vitamin B12, and SAM
Folate is the source of THF
Folate->dihydrofolate->THF (via dihydrofolate reductase, DHFR) in a 2 step reaction thats inhibited by methotrexate (that interferes with DNA synthesis), methotrexate decreases SAM pathway
Major players in One carbon metabolism
THF produced from folate (serine is the major source). B12 transfers a methyl group making methionine. SAM is produced from methionine and ATP
Folate and Sam pathways intersect:
Folate is used for purine synthesis, DNA synthesis, and synthesis of methionine (for SAM pathway)
SAM- Methylation
Megablastic anemia
Amino Acid biosynthesis
Essential- dont get synthesized
Non-essential: are synthesized in the liver. Required in high quantities because they are important for protein synthesis of other molecules
Amino Acid Biosythesis precursors
see notes
Tryptophan derivatives
Serotonin, melatonin, Niacin (NAD, and NADP)
See notes for details of pathway
AA metabolism
see notes
