Linked Life Data

3790572

Source:http://linkedlifedata.com/resource/pubmed/id/3790572

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1987-1-27
pubmed:abstractText
Fourier transform infrared spectroscopy was used to investigate the small conformational differences which exist between ribonuclease A and ribonuclease S in aqueous systems. Deconvolution and derivative methods were used to observe the overlapping components of the amide I and II bands. These proteins give identical spectra in H2O and after complete exchange in 2H2O. However structural differences are revealed by monitoring the rate of 1H-2H exchange by Fourier transform infrared spectroscopy. At equivalent times of exposure in 2H2O buffer ribonuclease S undergoes greater isotopic exchange than ribonuclease A. Thus complete exchange takes place for ribonuclease S but not ribonuclease A after incubation at room temperature for 8 days. Complete 1H-2H exchange of ribonuclease A was achieved by incubation at 62 degrees C for 30 min. The available X-ray data and comparison with the infrared spectra of other soluble proteins was used to assign the components of the amide I and II bands to various secondary structures. In particular, band shifts observed during the later stages of exchange are associated with slowly exchanging residues in beta-strand and alpha-helical regions. The higher rate of exchange for ribonuclease S is associated with a greater conformational flexibility and a more open structure. The results show that it is necessary to be cautious in making band assignments based on exchange methods unless the extent of exchange is known. Furthermore, it is seen that the combination of Fourier transform infrared spectroscopy and hydrogen-deuterium exchange is a powerful technique for revealing small differences in protein secondary structure.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
874
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
255-65
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
A Fourier transform infrared investigation of the structural differences between ribonuclease A and ribonuclease S.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't