Isolation and sequence of complementary DNA encoding human extracellular superoxide dismutase

Journal Article · Tue Sep 01 04:00:00 EDT 1987 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.84.18.6340· OSTI ID:7143429

Hjalmarsson, K; Marklund, S L; Engstroem, A; Edlund, T

A complementary DNA (cDNA) clone from a human placenta cDNA library encoding extracellular superoxide dismutase has been isolated and the nucleotide sequence determined. The cDNA has a very high G + C content. EC-SOD is synthesized with a putative 18-amino acid signal peptide, preceding the 222 amino acids in the mature enzyme, indicating that the enzyme is a secretory protein. The first 95 amino acids of the mature enzyme show no sequence homology with other sequenced proteins and there is one possible N-glycosylation site (Asn-89). The amino acid sequence from residues 96-193 shows strong homology (approx. 50%) with the final two-thirds of the sequences of all know eukaryotic CuZn SODs, whereas the homology with the P. leiognathi CuZn SOD is clearly lower. The ligands to Cu and Zn, the cysteines forming the intrasubunit disulfide bridge in the CuZn SODs, and the arginine found in all CuZn SODs in the entrance to the active site can all be identified in EC-SOD. A comparison with bovine CuZn SOD, the three-dimensional structure of which is known, reveals that the homologies occur in the active site and the divergencies are in the part constituting the subunit contact area in CuZn SOD. Amino acid sequence 194-222 in the carboxyl-terminal end of EC-SOD is strongly hydrophilic and contains nine amino acids with a positive charge. This sequence probably confers the affinity of EC-SOD for heparin and heparan sulfate. An analysis of the amino acid sequence homologies with CuZn SODs from various species indicates that the EC-SODs may have evolved form the CuZn SODs before the evolution of fungi and plants.

• Research Organization: SYN-TEK AB, Umea (Sweden)
• OSTI ID: 7143429
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 84:18; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINES
AMINO ACID SEQUENCE
ANIMALS
AROMATICS
AZAARENES
AZINES
BACTERIA
BACTERIOPHAGES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EVOLUTION
CLONING
COPPER COMPOUNDS
CYTOSINE
DAYS LIVING RADIOISOTOPES
DNA
DNA SEQUENCING
DNA-CLONING
ENZYMES
ESCHERICHIA COLI
ESTERASES
EVEN-ODD NUCLEI
FETAL MEMBRANES
GUANINE
HETEROCYCLIC COMPOUNDS
HYDROLASES
HYDROXY COMPOUNDS
ISOTOPES
LIGHT NUCLEI
MAMMALS
MAN
MEMBRANES
MICROORGANISMS
MOLECULAR STRUCTURE
NUCLEASES
NUCLEI
NUCLEIC ACIDS
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
OXIDOREDUCTASES
PARASITES
PHOSPHODIESTERASES
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PLACENTA
PRIMATES
PURINES
PYRIMIDINES
RADIOISOTOPES
RECOMBINANT DNA
STRUCTURAL CHEMICAL ANALYSIS
SULFUR 35
SULFUR ISOTOPES
SUPEROXIDE DISMUTASE
TRANSITION ELEMENT COMPOUNDS
VERTEBRATES
VIRUSES