Linked Life Data

1577725

Source:http://linkedlifedata.com/resource/pubmed/id/1577725

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1992-6-5
pubmed:abstractText
Few experimental models have been used to investigate how proteins fold inside a cell. Using the formation of disulfide bonds as an index of conformational changes during protein folding, we have developed a unique system to determine the intracellular folding pathway of the beta subunit of human chorionic gonadotropin (hCG). Three folding intermediates of the beta subunit were purified from [35S]cysteine-labeled JAR choriocarcinoma cells by immunoprecipitation and by reverse-phase high performance liquid chromatography (HPLC). To identify unformed disulfide bonds, nonreduced folding intermediates were treated with trypsin to liberate non-disulfide-bound, [35S]cysteine-containing peptides from the disulfide-linked peptides. Released peptides were purified by HPLC and identified by amino acid sequencing. The amount of a peptide that was released indicated the extent of disulfide bond formation involving the cysteine in that peptide. Of the six disulfide bonds in hCG-beta, bonds 34-88 and 38-57 form first. The rate-limiting event of folding involves the formation of the S-S bonds between cysteines 23 and 72 and cysteines 9 and 90. Disulfide bond 93-100, the formation of which appears to be necessary for assembly with the alpha subunit of the hCG heterodimer, forms next. Finally, disulfide bond 26-110 forms after assembly with the alpha subunit, suggesting that completion of folding of the COOH terminus in the beta subunit occurs after assembly with the alpha subunit.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8870-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Intracellular folding pathway of human chorionic gonadotropin beta subunit.
pubmed:affiliation
Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha 68198-6805.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't