Abstract
We isolated cDNAs encoding xanthine dehydrogenase (XD; xanthine:NAD+ oxidoreductase, EC 1.1.1.204) from a human liver cDNA library. The complete nucleotide sequence of human XD was determined; the deduced amino acid sequence encoded a protein of 1336 amino acid residues of Mr 147,782. Human XD possessed many of the signature sequences typical of XDs from flies and rodents, including an unusual cysteine distribution, a potential 2Fe/2S binding site, and a putative molybdopterin cofactor binding domain. Analysis of potential NAD binding sites suggested a simple hypothesis for the conversion of human XD into the oxygen metabolite forming xanthine oxidase (XO; xanthine:oxygen oxidoreductase, EC 1.1.3.22). Using a human XD complementary RNA hybridization probe, we found a 5100-base RNA in human liver by RNA blot-hybridization analysis. This RNA exhibited tissue-specific distribution that may be pertinent to XD- and XO-mediated oxygen radical injury in ischemia/reperfusion and inflammation. A second 4500-base RNA was detected in some tissues and may arise through differential transcription termination.
Original language | English (US) |
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Pages (from-to) | 10690-10694 |
Number of pages | 5 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 90 |
Issue number | 22 |
DOIs | |
State | Published - Nov 15 1993 |
Keywords
- Ischemia
- Oxidative injury
- Oxygen radicals
- Reperfusion
ASJC Scopus subject areas
- General