Linked Life Data

19170491

Source:http://linkedlifedata.com/resource/pubmed/id/19170491

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2009-2-19
pubmed:abstractText
During folding of many proteins, molten globules are formed. These partially folded forms of proteins have a substantial amount of secondary structure but lack virtually all tertiary side-chain packing characteristic of native structures. Molten globules are ensembles of interconverting conformers and are prone to aggregation, which can have detrimental effects on organisms. Consequently, molten globules attract considerable attention. The molten globule that is observed during folding of flavodoxin from Azotobacter vinelandii is a kinetically off-pathway species, as it has to unfold before the native state of the protein can be formed. This intermediate contains helices and can be populated at equilibrium using guanidinium hydrochloride as denaturant, allowing the use of NMR spectroscopy to follow molten globule formation at the residue level. Here, we track changes in chemical shifts of backbone amides, as well as disappearance of resonances of unfolded apoflavodoxin, upon decreasing denaturant concentration. Analysis of the data shows that structure formation within virtually all parts of the unfolded protein precedes folding to the molten globule state. This folding transition is noncooperative and involves a series of distinct transitions. Four structured elements in unfolded apoflavodoxin transiently interact and subsequently form the ordered core of the molten globule. Although hydrophobic, tryptophan side chains are not involved in the latter process. This ordered core is gradually extended upon decreasing denaturant concentration, but part of apoflavodoxin's molten globule remains random coil in the denaturant range investigated. The results presented here, together with those reported on the molten globule of alpha-lactalbumin, show that helical molten globules apparently fold in a noncooperative manner.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1520-5126
pubmed:author
pubmed:issnType
Electronic
pubmed:day
25
pubmed:volume
131
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2739-46
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Noncooperative Formation of the off-pathway molten globule during folding of the alpha-beta parallel protein apoflavodoxin.
pubmed:affiliation
Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't