Linked Life Data

1991106

Source:http://linkedlifedata.com/resource/pubmed/id/1991106

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1991-3-14
pubmed:abstractText
The conformation and stability of Escherichia coli derived recombinant human interleukin 4 (rhuIL-4) have been examined by circular dichroism (CD). Protein unfolding was detected by ellipticity changes at 222 nm with increasing concentrations of guanidine hydrochloride (GdnHCl). The unfolding midpoint ([GdnHCl]1/2) was 3.7 M, the free energy of unfolding, (delta GDH2O), was 5.9 kcal/mol and the dependence of delta GD on the GdnHCl concentration (m) was 1.6 (kcal/mol)/M. This unfolding was demonstrated to be reversible upon removal of the GdnHCl by dialysis. Analysis of the far-UV CD spectrum indicated the presence of a high percentage of alpha-helical structure (ca. 73%). A small change in ellipticity was noted over the pH range 1.9-9.6, suggesting that the protein undergoes a minor conformational change with an apparent pKa of 4.17. Virtually complete biological activity, measured in vitro in a T-cell proliferation assay, was recovered following exposure to extreme values of pH (i.e., pH 3 and 10). An analysis of the near-UV CD spectrum indicated that the single tryptophan residue at position 91 was unconstrained and most likely exposed to the solvent. Titration with 4,4'-dithiodipyridine and 2-nitrothiosulfobenzoate established that the six cysteine residues in rhuIL-4 were involved in intramolecular disulfide linkages. These data support that rhuIL-4 has a highly stable three-dimensional structure.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1259-64
pubmed:dateRevised
2002-11-1
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Analysis of the conformation and stability of Escherichia coli derived recombinant human interleukin 4 by circular dichroism.
pubmed:affiliation
Department of Biotechnology-Biochemistry, Schering-Plough Research, Bloomfield, New Jersey 07003.
pubmed:publicationType
Journal Article