title: Elucidation of the 2-aminoethylphosphonate biosynthetic pathway in Tetrahymena pyriformis.
abstract: The biosynthetic reaction pathway leading to the natural product, 2-aminoethylphosphonate in Tetrahymena pyriformis has been elucidated. Incubation of [32P]PEP and [14C]PEP with T.pyriformis cellular homogenate fortified with Mg2+ and alanine/pyridoxal phosphate, yielded 2-aminoethylphosphonate as the minor reaction product (2-5% yield) and phosphoglycerate and pyruvate plus orthophosphate as the major products. Inclusion of thiamine pyrophosphate in the reaction mixture increased the yield of 2-aminoethylphosphonate by a factor of 10. Incubation of phosphonoacetaldehyde or phosphonopyruvate in the cellular homogenate also provided 2-aminoethylphosphonate. The cellular homogenate catalyzed the transformation of phosphonoacetaldehyde to 2-aminoethylphosphonate in an ca. 80% yield. However, the maximum yield of 2-aminoethylphosphonic acid obtained by use of phosphonopyruvate was only 15%. The major reaction pathways induced by treatment of phosphonopyruvate with the cellular extract involved its competitive conversion to PEP and pyruvate plus orthophosphate.
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives / Q000378:metabolism; D000409:Alanine / Q000378:metabolism; D000615:Aminoethylphosphonic Acid / Q000096:biosynthesis*; D000818:Animals; D008274:Magnesium / Q000378:metabolism; D015636:Magnesium Chloride; D009943:Organophosphorus Compounds / Q000096:biosynthesis*; D010728:Phosphoenolpyruvate / Q000378:metabolism; D011732:Pyridoxal Phosphate / Q000378:metabolism; D011773:Pyruvates / Q000378:metabolism; D013769:Tetrahymena pyriformis / Q000378:metabolism*; D013835:Thiamine Pyrophosphate / Q000378:metabolism
chemical_list: C026220:3-phosphonopyruvate; D009943:Organophosphorus Compounds; D011773:Pyruvates; D015636:Magnesium Chloride; C003126:phosphonoacetaldehyde; D011732:Pyridoxal Phosphate; D010728:Phosphoenolpyruvate; D000615:Aminoethylphosphonic Acid; D000079:Acetaldehyde; D008274:Magnesium; D000409:Alanine; D013835:Thiamine Pyrophosphate