Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1999-2-25
pubmed:abstractText
Hsp20 is one of the newly described members of the mammalian small heat-shock protein (sHsp) family. It occurs most abundantly in skeletal muscle and heart. We isolated clones for Hsp20 from a rat heart cDNA library, and expressed the protein in Escherichia coli to characterize this little known sHsp. Recombinant Hsp20 displayed similar far-ultraviolet circular dichroism spectra as the most closely related sHsp, alpha B-crystallin, but was less heat stable, denaturing upon heating to 50 degrees C. While other mammalian recombinant sHsps form large multimeric complexes, Hsp20 occurs in two complex sizes, 43-kDa dimers and 470-kDa multimers. The ratio between the two forms depends on protein concentration. Moreover, Hsp20 has a much lower chaperone-like activity than alpha B-crystallin, as indicated by its relatively poor capacity to diminish the reduction-induced aggregation of insulin B chains. Hsp20 is considerably shorter at the C-terminus and less polar than other sHsps, but 1H-NMR spectroscopy reveals that the last 10 residues are flexible, as in the other sHsps. Our findings suggest that Hsp20 is a special member of the sHsp family in being less heat stable and tending to form dimers. These properties, together with the shorter and less polar C-terminal extension, may contribute to the less effective chaperone-like activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
258
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1014-21
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
The mammalian small heat-shock protein Hsp20 forms dimers and is a poor chaperone.
pubmed:affiliation
Department of Biochemistry, University of Nijmegen, The Netherlands.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't