Purity: > 90% by SDS - PAGE Format: Liquid. In 20mM Tris-HCl buffer (pH 8.0) containing 1mM DTT, 20% glycerol, 50mM NaCl. 4-hydroxyphenylpyruvate dioxygenase isoform 1, also known as HPD, is an Fe-containing enzyme, that catalyzes the second reaction in the catabolism of tyrosine the conversion of 4-hydroxyphenylpyruvate to homogentisate. Existing as a homodimer, HPD uses zinc as a cofactor to catalyze the third step in the conversion of L-phenylalanine to fumarate and acetoacetic acid. Defects in the gene encoding HPD are the cause of tyrosinemia type 3 and hawkinsinuria, both of which are inborn errors of metabolism that are associated with a variety of symptoms, including mental retardation and seizures and hair and urine abnormalities. Recombinant human HPD protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.