Source:http://linkedlifedata.com/resource/pubmed/id/12962499
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
36
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| pubmed:dateCreated |
2003-9-9
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| pubmed:abstractText |
The molecular chaperone function of alpha-crystallin in the lens prevents the aggregation and insolubilization of lens proteins that occur during the process of aging. We found that chemical modification of alpha-crystallin by a physiological alpha-dicarbonyl compound, methylglyoxal (MG), enhances its chaperone function. Protein-modifying sugars and ascorbate have no such effect and actually reduce chaperone function. Chaperone assay after immunoprecipitation or with immunoaffinity-purified argpyrimidine-alpha-crystallin indicates that 50-60% of the increased chaperone function is due to argpyrimidine-modified protein. Incubation of alpha-crystallin with DL-glyceraldehyde and arginine-modifying agents also enhances chaperone function, and we believe that the increased chaperone activity depends on the extent of arginine modification. Far- and near-UV circular dichroism spectra indicate modest changes in secondary and tertiary structure of MG-modified alpha-crystallin. LC MS/MS analysis of MG-modified alpha-crystallin following chymotryptic digestion revealed that R21, R49, and R103 in alphaA-crystallin were converted to argpyrimidine. 1,1'-Bis(4-anilino)naphthalene-5,5'-disulfonic acid binding, an indicator of hydrophobicity of proteins, increased in alpha-crystallin modified by low concentrations of MG (2-100 microM). MG similarly enhances chaperone function of another small heat shock protein, Hsp27. Our results show that posttranslational modification by a metabolic product can enhance the chaperone function of alpha-crystallin and Hsp27 and suggest that such modification may be a protective mechanism against environmental and metabolic stresses. Augmentation of the chaperone function of alpha-crystallin might have evolved to protect the lens from deleterious protein modifications associated with aging.
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| pubmed:grant | |
| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Alcohol Dehydrogenase,
http://linkedlifedata.com/resource/pubmed/chemical/Anilino Naphthalenesulfonates,
http://linkedlifedata.com/resource/pubmed/chemical/Arginine,
http://linkedlifedata.com/resource/pubmed/chemical/Ascorbic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Citrate (si)-Synthase,
http://linkedlifedata.com/resource/pubmed/chemical/Insulin,
http://linkedlifedata.com/resource/pubmed/chemical/Lysine,
http://linkedlifedata.com/resource/pubmed/chemical/Molecular Chaperones,
http://linkedlifedata.com/resource/pubmed/chemical/Monosaccharides,
http://linkedlifedata.com/resource/pubmed/chemical/Ornithine,
http://linkedlifedata.com/resource/pubmed/chemical/Pyrimidines,
http://linkedlifedata.com/resource/pubmed/chemical/Pyruvaldehyde,
http://linkedlifedata.com/resource/pubmed/chemical/alpha-Crystallins,
http://linkedlifedata.com/resource/pubmed/chemical/argpyrimidine
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| pubmed:status |
MEDLINE
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| pubmed:month |
Sep
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| pubmed:issn |
0006-2960
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
16
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| pubmed:volume |
42
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
10746-55
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| pubmed:dateRevised |
2011-11-17
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| pubmed:meshHeading |
pubmed-meshheading:12962499-Alcohol Dehydrogenase,
pubmed-meshheading:12962499-Anilino Naphthalenesulfonates,
pubmed-meshheading:12962499-Animals,
pubmed-meshheading:12962499-Arginine,
pubmed-meshheading:12962499-Ascorbic Acid,
pubmed-meshheading:12962499-Cattle,
pubmed-meshheading:12962499-Citrate (si)-Synthase,
pubmed-meshheading:12962499-Humans,
pubmed-meshheading:12962499-Insulin,
pubmed-meshheading:12962499-Lens, Crystalline,
pubmed-meshheading:12962499-Lysine,
pubmed-meshheading:12962499-Middle Aged,
pubmed-meshheading:12962499-Molecular Chaperones,
pubmed-meshheading:12962499-Monosaccharides,
pubmed-meshheading:12962499-Ornithine,
pubmed-meshheading:12962499-Protein Structure, Secondary,
pubmed-meshheading:12962499-Protein Structure, Tertiary,
pubmed-meshheading:12962499-Pyrimidines,
pubmed-meshheading:12962499-Pyruvaldehyde,
pubmed-meshheading:12962499-alpha-Crystallins
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| pubmed:year |
2003
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| pubmed:articleTitle |
Enhancement of chaperone function of alpha-crystallin by methylglyoxal modification.
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| pubmed:affiliation |
Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio 44106-5068, USA. nhr@po.cwru.edu
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| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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