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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
25
|
| pubmed:dateCreated |
1997-7-21
|
| pubmed:abstractText |
Purified human apolipoprotein A-I (apoA-I), when run across a transverse urea gradient at alkaline pH, gives a complex pattern characterized by a number of parallel sigmoidal curves, in which the transition between high- and low-mobility forms, i.e. from folded to unfolded structure, occurs between 1.1 and 3.2 M urea. Size differences appear to be the major cause of this isomerism. When migrated across a wide pH range in the presence of varying amounts of urea to display its titration curve, apoA-I is resolved into two pairs of bands, running parallel in the neutral to basic pH region while merging at acidic pH; such a finding does not correlate with a differential exposure of His residues, as shown by diethyl pyrocarbonate titration. Ferguson plot analysis, confirmed by cross-linking experiments, demonstrates a gradual shift from higher to lower mass aggregates as the urea concentration is raised; the monomeric form undergoes denaturation by swelling to an approximately 50% larger hydrodynamic volume than in its native state. At alkaline pH, where apoA-I exists as aggregated species, disaggregation and unfolding appear to happen at once, the larger aggregates being less stable than the smaller ones. At acidic pH, apoA-I does not form aggregates and has little secondary structure; unfolding is then a progressive rather than a cooperative process.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jun
|
| pubmed:issn |
0006-2960
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
24
|
| pubmed:volume |
36
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
7898-905
|
| pubmed:dateRevised |
2004-11-17
|
| pubmed:meshHeading | |
| pubmed:year |
1997
|
| pubmed:articleTitle |
Denaturation and self-association of apolipoprotein A-I investigated by electrophoretic techniques.
|
| pubmed:affiliation |
Istituto di Scienze Farmacologiche and Centro Enrica Grossi Paoletti, Facoltà di Farmacia, Università di Milano, Italy. gianazza@isfunix.farma.unimi.it
|
| pubmed:publicationType |
Journal Article
|