4-Hydroxyphenylpyruvic acid explained

4-Hydroxyphenylpyruvic acid (4-HPPA) is an intermediate in the metabolism of the amino acid phenylalanine. The aromatic side chain of phenylalanine is hydroxylated by the enzyme phenylalanine hydroxylase to form tyrosine. The conversion from tyrosine to 4-HPPA is in turn catalyzed by tyrosine aminotransferase.^[1] Additionally, 4-HPPA can be converted to homogentisic acid which is one of the precursors to ochronotic pigment.^[2]

It is an intermediary compound in the biosynthesis of scytonemin.

See also

• 4-Hydroxyphenylpyruvate dioxygenase

Notes and References

1. Brand. Larry. Harper, Alfred. Biochemical Journal. 1974. 142. 231–45. 1168273. Effect of glucagon on phenylalanine metabolism and phenylalanine-degrading enzymes in the rat. 2. 10.1042/bj1420231 . 4155291.
2. Denoya. Claudio. Skinner, Deborah. Morgenstern, Margaret. A Streptomyces avermitilis gene encoding a 4-hydroxyphenylpyruvic acid dioxygenase-like protein that directs the production of homogentisic acid and an ochronotic pigment in Escherichia coli. Journal of Bacteriology. September 1994. 1. 17. 5312–5319. 10.1128/jb.176.17.5312-5319.1994 . 8071207 . 196716.