Linked Life Data

11010965

Source:http://linkedlifedata.com/resource/pubmed/id/11010965

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-3-6
pubmed:abstractText
We have investigated the mechanisms that target oxidized calmodulin for degradation by the proteasome. After methionine oxidation within calmodulin, rates of degradation by the 20 S proteasome are substantially enhanced. Mass spectrometry was used to identify the time course of the proteolytic fragments released from the proteasome. Oxidized calmodulin is initially degraded into large proteolytic fragments that are released from the proteasome and subsequently degraded into small peptides that vary in size from 6 to 12 amino acids. To investigate the molecular determinants that result in the selective degradation of oxidized calmodulin, we used circular dichroism and fluorescence spectroscopy to assess oxidant-induced structural changes. There is a linear correlation between decreases in secondary structure and the rate of degradation. Calcium binding or the repair of oxidized calmodulin by methionine sulfoxide reductase induces comparable changes in alpha-helical content and rates of degradation. In contrast, alterations in the surface hydrophobicity of oxidized calmodulin do not alter the rate of degradation by the proteasome, indicating that changes in surface hydrophobicity do not necessarily lead to enhanced proteolytic susceptibility. These results suggest that decreases in secondary structure expose proteolytically sensitive sites in oxidized calmodulin that are cleaved by the proteasome in a nonprocessive manner.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
937-43
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:11010965-Adenosine Triphosphatases, pubmed-meshheading:11010965-Amino Acid Sequence, pubmed-meshheading:11010965-Animals, pubmed-meshheading:11010965-Calmodulin, pubmed-meshheading:11010965-Cysteine Endopeptidases, pubmed-meshheading:11010965-Kinetics, pubmed-meshheading:11010965-Liver, pubmed-meshheading:11010965-Mass Spectrometry, pubmed-meshheading:11010965-Methionine Sulfoxide Reductases, pubmed-meshheading:11010965-Molecular Sequence Data, pubmed-meshheading:11010965-Multienzyme Complexes, pubmed-meshheading:11010965-Oxidation-Reduction, pubmed-meshheading:11010965-Oxidoreductases, pubmed-meshheading:11010965-Peptide Fragments, pubmed-meshheading:11010965-Proteasome Endopeptidase Complex, pubmed-meshheading:11010965-Rats, pubmed-meshheading:11010965-Rats, Inbred F344, pubmed-meshheading:11010965-Substrate Specificity
pubmed:year
2001
pubmed:articleTitle
Selective degradation of oxidized calmodulin by the 20 S proteasome.
pubmed:affiliation
Department of Ophthalmology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't