Utuversity of Alberta Hospital, Edmonton 61, Alberta, Canada. For reprints, write D. J. C., Division of Clinical Chemistry, Department of Pathology, Vancouver General Hospital, Vancouver, B. C., Canada. ‘Nonstandard abbreviations used: not’, 4-desoxypyridoxine; pHPPA, p-hydroxyphenylpyruvic acid; PHPAA, p-hydroxyphenylacetic acid; pHyLA, p-hydroxyphenyllactic acid; VMA, vanillylmandelic acid (4...

The complete catabolic pathway involved in the assimilation of 3-hydroxyphenylacetic acid (3-OH-PhAc) in Pseudomonas putida U has been established. This pathway is integrated by the following: (i) a specific route (upper pathway), which catalyzes the conversion of 3-OH-PhAc into 2,5-dihydroxyphenylacetic acid (2,5-diOH-PhAc) (homogentisic acid, Hmg), and (ii) a central route (convergent route),...

Alkaptonuria is a rare metabolic disorder characterized by a deficiency of the homogentisic acid oxidase enzyme. The result is accumulation of homogentisic acid in collagenous structures throughout the body, especially in fibrous and cartilaginous tissue. This leads to gradual development of a phenomenon known as ochronosis. Characteristic features of ochronosis are urine darkening, progressive...

BACKGROUND Alkaptonuria, caused by a deficiency of homogentisate 1,2-dioxygenase, results in the accumulation of homogentisic acid (2,5-dihydroxyphenylacetic acid, HGA) in the urine. Alkaptonuria is suspected when the urine changes color after it is left to stand at room temperature for several hours to days; oxidation of homogentisic acid to benzoquinone acetic acid underlies this color change...