Linked Life Data

8394123

Source:http://linkedlifedata.com/resource/pubmed/id/8394123

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
32
pubmed:dateCreated
1993-9-16
pubmed:abstractText
The effect of pH on the conformational stability of insulin was studied. Surprisingly, the Gibbs free energy of unfolding increased approximately 30% by acidification. pH titration of insulin's conformational stability is described by a transition involving a single proton with an apparent pK(a) of 7.0. The acid stabilization of insulin's conformation was attributed to the protonation of histidine at position 5 on the B-chain (HB5) as determined by 1H-NMR of the histidines, selective amino acid alteration, and enthalpies of ionization. Further acidification (at least to pH 2) does not decrease the free energy of unfolding. A conformational change in the tertiary structure, as indicated by the near-UV circular dichroism spectrum, accompanies this change in stability. We propose that this acid stabilization of insulin is physiologically important in maintaining insulin stability in the acid environment of the secretory/storage granules of the beta-cell of the pancreatic islets of Langerhans.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8075-82
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Acid stabilization of insulin.
pubmed:affiliation
Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46285.
pubmed:publicationType
Journal Article