Codecarboxylase

Pyridoxamine phosphate. CbH13n205P. 2-methyl 3 hydr-oxy-4-aminomethyl-5-pyridylmethylphosphoric acid. Prepn in soin by autoclaving codecarboxylase with glutamic acid McNutt, Snell, J. Biol Chem 182, 557 (1950) prepn by direct phosphorylation of pyridoxamine in aq soin with phosphorus oxychloride Heyl er al. J. Am. Chem Soc. 73, 3430 (1951). 

Code 321. See Hydrogenated soybean oil Codecarboxylase. See Pyridoxal 5-phosphate Cod liver oil... 

Pyridone Pyridone-2 2(1 H)-Pyridone a-Pyridone. See 1-Hydroxy-2-pyridine Pyridoxaldehyde phosphate Pyridoxal, 5-(dihydrogen phosphate) Pyridoxal monophosphate Pyridoxal P Pyridoxal phosphate. See Pyridoxal 5-phosphate Pyridoxal 5-phosphate CAS 54-47-7 41468-25-1 (monohydrate) EINECS/ELINCS 200-208-3 Synonyms Codecarboxylase 3-Hydroxy-2-methyl-5-[(phosphonooxy) methyl]-4-pyridinecarboxaldehyde Phosphopyridoxal Phosphoridoxal coenzyme 4-Pyridinecarboxaldehyde, 3-hydroxy-2-methyl-5-[(phosphonooxy) methyl]-Pyridoxaldehyde phosphate Pyridoxal, 5-(dihydrogen phosphate) Pyridoxal monophosphate Pyridoxal P Pyridoxal phosphate Pyridoxyl phosphate Classification Organic compd. 

Pyridoxal Phosphate, Codecarboxylase. An independent approach to the nature of the amino acid decarboxylases was made by Gunsalus, Umbreit, and collaborators. They found that the production of tyrosine decarboxylase by Streptococcus faecalis depended on the vitamin, pyri-doxine. In the absence of pyridoxine the cells grew but had little decarboxylase. However, addition of the vitamin permitted deficient cells to decarboxylate tyrosine, and dried cells exhibited active enzyme in the presence of pyridoxal (a derivative of pyridoxine) and ATP, implying the formation of an active cofactor from these substances. Pyridoxal is a more active growth factor for a strain of Streptococcus faecalis than pyridoxine both synthetic pyridoxal and pyridoxamine exhibit 5000 to 9000 times the activity of the hydroxy compound. ... 

Interesting differences of opinion enlivened efforts to elucidate the structure of the active cofactor. Eventually it was established by Umbreit and Gunsalus that codecarboxylase is pyridoxal phosphorylated on the hydroxymethyl group at position 5. ... 

The prosthetic group of both enzymes has been identified with phosphopyridoxal. Using an enzjunatic assay with dopa-apodecarboxylase, Green and associates (173) found a codecarboxylase activity corresponding to a content of 0.55 ng. phosphopyridoxal per mg. of maximally purified aph(,i g (Q= 14,400), and to 0.27 ng. phosphopyridoxal per mg. of... 

Karrer and Viscontini synthesized the acetal of pyridoxal-3-phosphate and claimed that it had codecarboxylase activity but could not reactivate a transaminase system. In the meantime, Gunsalus presented evidence that the active synthetic product was not the 3-phosphate (and by elimination must be the 5-phosphate). This discrepancy was resolved when the two products were compared simultaneously on the same test system. The activity of the 3-phosphate was so low compared to the active pyridoxal phosphate that the 3-phosphate was definitely ruled out as the active coenzyme. In a recent series of papers,the structure of pyridoxal phosphate is definitely established as pyridoxal-5-phosphate and that of pyridoxamine-phosphate as the 5 phosphate. 

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