Linked Life Data

18938150

Source:http://linkedlifedata.com/resource/pubmed/id/18938150

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2008-12-1
pubmed:abstractText
A lipoprotein-like antifreeze protein (type IV AFP) has previously been isolated only from the blood plasma of the longhorn sculpin. However, the plasma antifreeze activity in all individuals of this species tested from Newfoundland and New Brunswick waters ranges from low to undetectable. A close relative of the longhorn sculpin, the shorthorn sculpin, does have appreciable antifreeze activity in its blood but this is virtually all accounted for by the alpha-helical, alanine-rich type I AFP, other isoforms of which are also present in the skin of both fishes. We have characterized a putative ortholog of type IV AFP in shorthorn sculpin by cDNA cloning. This 12.2-kDa Gln-rich protein is 87% identical to the longhorn sculpin's type IV AFP. Recombinant versions of both orthologs were produced in bacteria and shown to have antifreeze activity. Immunoblotting with antibodies raised to type IV AFP shows this protein present in longhorn sculpin plasma at levels of less than 100 microg/mL, which are far too low to protect the blood from freezing at the temperature of icy seawater. This confirms the results of direct antifreeze assays on the plasmas. It appears that type IV AFP has the potential to develop as a functional antifreeze in these fishes but may not have been selected for this role because of the presence of type I AFP. Consistent with this hypothesis is the observation that the type IV AFP gene has not been amplified the way functional antifreeze protein genes have in all other species examined.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1090-2392
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
57
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
292-6
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
A re-evaluation of the role of type IV antifreeze protein.
pubmed:affiliation
Department of Biochemistry, Queen's University, Kingston, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't