Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:2.3.3.1 (
citrate synthase
)
4,488
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Beta-synuclein exhibits high sequence homology and structural similarity with
alpha-synuclein
, a protein implicated in the pathogenesis of Parkinson's disease. We investigated the chaperone function of beta-synuclein and its anti-fibrillar activity in comparison with
alpha-synuclein
. beta-Synuclein suppressed the heat-induced aggregation of aldolase, alcohol dehydrogenase, and
citrate synthase
, and its anti-aggregative activity was remarkably higher than that of
alpha-synuclein
. Heat-induced inactivation of
citrate synthase
was significantly protected by beta-synuclein. Moreover, beta-synuclein inhibited the amyloid formation of both Abeta(1-40) and
alpha-synuclein
. It is, therefore, suggested that beta-synuclein can prevent abnormal protein aggregations more effectively than
alpha-synuclein
by acting as a molecular chaperone.
...
PMID:Beta-synuclein exhibits chaperone activity more efficiently than alpha-synuclein. 1547 47
Phosphorylation appears to be one of the modulators of chaperone functions of small heat shock proteins. However, the role of phosphorylation is not completely understood. We have investigated the structural and functional consequences of a phosphorylation-mimicking mutation in alpha B-crystallin, a small heat shock protein with chaperone activity. We have used a phosphorylation-mimicking mutant, 3D alpha B-crystallin, in which all the three phosphorylatable serine residues are replaced with aspartic acid. 3D alpha B-Crystallin showed enhanced chaperone-like activity towards DTT-induced aggregation of insulin, heat-induced aggregation of
citrate synthase
and SDS-induced amyloid fibril formation of
alpha-synuclein
. Fluorescence and circular dichroism spectroscopic studies showed that 3D alpha B-crystallin exhibits lower stability towards urea-induced denaturation compared to alpha B-crystallin. Subunit exchange studies using fluorescence resonance energy transfer showed that 3D alpha B-crystallin exhibits an observable increase in subunit exchange compared to alpha B-crystallin. Since only part of alpha B-crystallin is phosphorylated in vivo, our subunit exchange studies indicate that formation of mixed oligomers between the unphosphorylated and phosphorylated subunits are likely to play a role in vivo. Our study shows that mixed-oligomer formation modulates the chaperone-like activity. We propose that the degree of phosphorylation of the alpha B-crystallin oligomers and temperature are key modulators to achieve a wide range of chaperone capabilities of the small heat shock protein, alpha -crystallin.
...
PMID:Effect of phosphorylation on alpha B-crystallin: differences in stability, subunit exchange and chaperone activity of homo and mixed oligomers of alpha B-crystallin and its phosphorylation-mimicking mutant. 1806 12
