Faculty Collaboration Database

Characterization of the pigment from homogentisic acid and urine and tissue from an alkaptonuria patient. Biochem Cell Biol 1991 Apr;69(4):269-73

Date

04/01/1991

Pubmed ID

1647170

DOI

10.1139/o91-041

Scopus ID

2-s2.0-0026149212 (requires institutional sign-in at Scopus site)   27 Citations

Abstract

When urine samples from alkaptonuria patients are allowed to stand, they turn black, presumably owing to the oxidation of homogentisic acid to a melanin-like substance. We report the characterization of the pigments formed by polymerization of (a) the components in the urine from a patient with alkaptonuria and (b) homogentisic acid. The absorption spectra and electron spin resonance signals of these pigments are similar to those of eumelanins. Irradiation of the pigments with nitroblue tetrazolium caused reduction of the tetrazolium; this was partially inhibited by superoxide dismutase. Irradiation of Ehrlich ascites carcinoma cells with the pigments from homogentisic acid or urine caused cell lysis. Since this lysis was inhibited by catalase, we have concluded that it was mediated by H2O2. A similar pigment was also extracted from the tissue from an alkaptonuria patient. It is suggested that the degeneration of tissue in vivo may be due to the deposition of melanin-like pigments in the tissues, probably in combination with metal ions.

Author List

Menon IA, Persad SD, Haberman HF, Basu PK, Norfray JF, Felix CC, Kalyanaraman B

Author

Balaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Alkaptonuria
Catalase
Electron Spin Resonance Spectroscopy
Homogentisic Acid
Humans
Melanins
Nitroblue Tetrazolium
Oxidation-Reduction
Pigments, Biological
Spectrophotometry, Ultraviolet
Superoxide Dismutase
Tumor Cells, Cultured
Ultraviolet Rays