Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1993-3-23
pubmed:databankReference
pubmed:abstractText
A copper,zinc superoxide dismutase, has been isolated from the marine turtle Caretta caretta and the complete amino acid sequence obtained. The sequence was determined by isolation and analysis of peptides obtained after cleavage of the carboxymethylated apoenzyme with trypsin or Staphylococcus aureus protease. Turtle superoxide dismutase consists of 166 amino acid residues, which represents the largest number to date for a cytosolic copper,zinc superoxide dismutase. The comparison of this amino acid sequence with that of bovine superoxide dismutase revealed a one-residue C-terminal extension, two single residue insertions and a 12-residue insertion in the N-terminal region, in turtle superoxide dismutase. The new segment consists of a threefold repeating sequence and was found to be the site for selective proteolytic attack by trypsin under native conditions. The biochemical characteristics, the spectroscopic and catalytic properties as well as the thermal stability and the resistance to irreversible denaturation, were carefully examined and were very similar to those of other superoxide dismutases. These results indicate that the presence of the new polypeptide segment does not affect the main folding of the chain and the quaternary structure, nor the functional parameters of turtle superoxide dismutase. The possibility that the new insert constitutes a loop excluded from the protein scaffold providing the framework of the active site is also discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
211
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
843-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
The primary structure of turtle Cu,Zn superoxide dismutase. Structural and functional irrelevance of an insert conferring proteolytic susceptibility.
pubmed:affiliation
Department of Biochemical Sciences, University of Rome La Sapienza, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't