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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
16
|
| pubmed:dateCreated |
1998-5-21
|
| pubmed:abstractText |
alpha-Crystallin is a multimeric protein that has been shown to function as a molecular chaperone. Present investigations were undertaken to understand its mechanism of chaperoning. For this functional in vitro analysis of alpha-crystallin we used xylose reductase (XR) from Neurospora crassa as the model system. Denaturation studies using the structure-perturbing agent guanidinium chloride indicated that XR folds through a partially folded state that resembles the molten globule. Fluorescence and delay experiments revealed that alpha-crystallin interacts with the molten globule state of XR (XR-m) and prevents its aggregation. Cold lability of alpha-crystallin.XR-m interaction was revealed by temperature shift experiments implicating the involvement of hydrophobic interactions in the formation of the complex. Reconstitution of active XR was observed on cooling the alpha-crystallin.XR-m complex to 4 degrees C or on addition of ATP at 37 degrees C. ATP hydrolysis is not a prerequisite for XR release since the nonhydrolyzable analogue 5'-adenylyl imidodiphosphate (AMP-PNP) was capable of reconstitution of active XR. Experimental evidence has been provided for temperature- and ATP-mediated structural changes in the alpha-crystallin.XR-m complex that shed some light on the mechanism of reconstitution of active XR by this chaperone. The relevance of our finding to the role of alpha-crystallin in vivo is discussed.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Apr
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
17
|
| pubmed:volume |
273
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
9415-23
|
| pubmed:dateRevised |
2000-12-18
|
| pubmed:meshHeading |
pubmed-meshheading:9545266-Aldehyde Reductase,
pubmed-meshheading:9545266-Circular Dichroism,
pubmed-meshheading:9545266-Crystallins,
pubmed-meshheading:9545266-Guanidine,
pubmed-meshheading:9545266-Kinetics,
pubmed-meshheading:9545266-Molecular Chaperones,
pubmed-meshheading:9545266-Neurospora crassa,
pubmed-meshheading:9545266-Protein Conformation,
pubmed-meshheading:9545266-Protein Denaturation,
pubmed-meshheading:9545266-Protein Folding,
pubmed-meshheading:9545266-Spectrometry, Fluorescence
|
| pubmed:year |
1998
|
| pubmed:articleTitle |
Interactions of chaperone alpha-crystallin with the molten globule state of xylose reductase. Implications for reconstitution of the active enzyme.
|
| pubmed:affiliation |
Division of Biochemical Sciences, National Chemical Laboratory, Pune 411008, India.
|
| pubmed:publicationType |
Journal Article
|