Linked Life Data

1888739

Source:http://linkedlifedata.com/resource/pubmed/id/1888739

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
36
pubmed:dateCreated
1991-10-17
pubmed:abstractText
We have examined the influence of monovalent and divalent cations on the secondary structure of bovine alpha-lactalbumin at neutral pH using Fourier-transform infrared spectroscopy. Our present studies are based on previously reported amide I' component band assignments for this protein [Prestrelski, S. J., Byler, D. M., & Thompson, M. P. (1991) Int. J. Pept. Protein Res. 37, 508-512]. The results indicate that upon dissolution, alpha-lactalbumin undergoes a small, but significant, time-dependent conformational change, regardless of the ions present. Additionally, these studies provide the first quantitative measure of the well-known secondary structural change which accompanies calcium binding. Results indicate that removal of Ca2+ from holo alpha-lactalbumin results in local unfolding of the Ca(2+)-binding loop; the spectra indicate that approximately 16% of the backbone chain changes from a rigid coordination complex to an unordered loop. We have also examined the effects of binding of several other metal ions. Our studies have revealed that binding of Mn2+ to apo alpha-lactalbumin (Ca(2+)-free), while inducing a small, but significant, conformational change, does not cause the alpha-lactalbumin backbone conformation to change to that of the holo (Ca(2+)-bound) form as characterized by infrared spectroscopy. Similar changes to those induced by Mn2+ are observed upon binding of Na+ to apo alpha-lactalbumin, and furthermore, even at very high concentrations (0.2 M), Na+ does not stabilize a structure similar to the holo form. Binding of Zn2+ to the apo form of alpha-lactalbumin does not result in significant backbone conformational changes, suggesting a rigid Zn(2+)-binding site.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8797-804
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Effect of metal ion binding on the secondary structure of bovine alpha-lactalbumin as examined by infrared spectroscopy.
pubmed:affiliation
Eastern Regional Research Center, U.S. Department of Agriculture, Philadelphia, Pennsylvania 19118.
pubmed:publicationType
Journal Article