Purine and pyrimidine nucleotides
Glycine is a precursor of porphyrins
- Heme proteins (hemoglobin, cytochromes)
- Heme = Porphyrins + Fe+++
- The first cyclic compound in the biosynthesis of porphyrins and heme is an asymmetric uroporphyrinogen III. Subsequent modifications of the side chains and alteration of the saturation of the porphyrin ring give rise to protoporphyrin IX. Addition of iron molecule to the last product yield heme.
- Heme is the prosthetic group many protein molecules (such as hemoglobim, myoglobin, catalase, peroxidase and cytochromes).
- Genetic defects affecting the synthesis of porphyrins
Synthesis of creatine and glutathione (= g-glutamayl-cysteinyl-glycine)
Glutathione is found in all cells and plays important role in maintaining the sulfhydryl groups of proteins in a reduced state.
Glutathione also acts as a reduce carrier for the reduction of glutaredoxin which is a hydrogen donor for nucleotide reductase.
Independent of its role with reducing power, glutathione also function as a g-glutamyl donor.
gama-glutamyl cycle and glutathione:
Aromatic amino acids as precursors of many plant substances
- Lignin (plant structural component) from Phenylalanine & Tyrosine
- Auxin (plant growth hormone) from Tryptophan
Decarboxylation of amino acids to biological amines
- Dopamine from Tyrosine (Parkinson's disease and Schizophrenia)
- Norepinephrine and epinephrine from Tyrosine
- GABA (r-aminobutyrate) from Glutamate
- Serotonin from Tryptophan
- Histamine (vasodilator) from Histidine
- Spermine and spermidine from Methionine
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