Primary structure of human plasma glutathione peroxidase deduced from cDNA sequences.
Human plasma glutathione peroxidase (GSHPx) has been shown to be a selenium-containing enzyme immunologically distinct from cellular GSHPx. Oligonucleotide probes, based on the partial amino acid sequence of plasma GSHPx, were synthesized and used to screen a human placenta cDNA library. Nucleotide sequence analysis of the obtained clones revealed that GSHPx consisted of a 678-base pair open reading frame coding for a 226-amino acid polypeptide with a Mr of 25,389. About 50% of the deduced amino acid sequence was confirmed by partial amino acid sequencing of the peptides in a lysine endopeptidase-digest of the purified enzyme. The amino acid sequence exhibited only 44% homology with that of human cellular GSHPx. Northern blot analysis revealed a single transcript of 2.2 kilobases in the poly(A)+ RNA fractions of human placenta and HepG2 (a human hepatic cell line), but not that of human liver and endothelial cells.
Takahashi
K
K
Department of Hygienic Chemistry, Faculty of Pharmaceutical Sciences, Hokkaido University.
Akasaka
M
M
Yamamoto
Y
Y
Kobayashi
C
C
Mizoguchi
J
J
Koyama
J
J
D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D003600:Cytosol / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D015342:DNA Probes; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood* / Q000737:chemistry; D006801:Humans; D008099:Liver / Q000737:chemistry / Q000166:cytology; D008969:Molecular Sequence Data; D010920:Placenta / Q000737:chemistry; D011247:Pregnancy
D015342:DNA Probes; D004247:DNA; D005979:Glutathione Peroxidase