Cloning and expression in vitro of human xanthine dehydrogenase/oxidase.
To study the expression of human xanthine dehydrogenase/oxidase (hXDH/XO), we cloned the cDNA covering its complete coding sequence and characterized it by translation in vitro in rabbit reticulocyte lysates and by transient expression in COS-1 cells. Two specific protein products with approximate molecular masses of 150 and 130 kDa were detected in both expression systems. These products are compatible with the molecular sizes of XDH/XO, and these peptides also showed immunoreactivity with polyclonal anti-hXDH antibodies. Significant XDH/XO enzyme activity (277 +/- 54 pmol/min per mg of protein) was measured in lysates of transfected COS cells, whereas in control transfections the activities were below the detection limit of our assay (0.2 pmol/min per mg of protein). The COS cells expressed the enzyme predominantly (89.8 +/- 0.3%) in the dehydrogenase form.
Saksela
M
M
Children's Hospital, University of Helsinki, Helsinki, Finland.
Raivio
K O
KO
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D015151:Immunoblotting; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D011817:Rabbits; D014968:Xanthine Dehydrogenase / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014969:Xanthine Oxidase / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
D018076:DNA, Complementary; D014968:Xanthine Dehydrogenase; D014969:Xanthine Oxidase