Structural Biochemistry/Enzyme/Phenylalanine Hydroxylase

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PAH catalyzed hydroxylation reaction.

Phenylalanine Hydroxylase (also known as PAH, PheOH, PheH) is an enzyme catalyzing hydroxylation of phenylalanine to make tyrosine. PAH is mainly found in liver and kidneys.[1] More than 500 mutations have been found for PAH.[1]

Mechanism[edit | edit source]

Like other aromatic amino acid hydroxylases, PAH follows these steps:

  1. FeII-O-O-BH4 bridge formation and cleavage of O-O bond to form FeIV=O complex
  2. Attack on FeIV=O to cause hydroxylation of the aromatic amino acid

Mutation[edit | edit source]

The most famous example of PAH mutation is related to the genetic disorder phenylketonuria. Patients with PKU have mutation in the PAH gene leading to inactivity of PAH, causing buildup of Phe and subsequent reduced mental development.

References[edit | edit source]

  1. a b Olsson, Elaine et al. "The Aromatic Amino Acid Hydroxylase Mechanism: A Perspective From Computational Chemistry." Theoretical and Computational Inorganic Chemistry 62 (2010): 437-