Linked Life Data

12943907

Source:http://linkedlifedata.com/resource/pubmed/id/12943907

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
2003-8-28
pubmed:abstractText
15N CPMAS, 13C CPMAS and 1H CRAMPS spectra of several polypeptide samples were compared to determine the useful features of each technique. 13C CPMAS is the most well-established technique and is useful for quick determination of secondary structure. The 15N nucleus is more sensitive to exact hydrogen-bonding parameters, which complicates interpretation of the spectra. However, it is better for resolving end effects and structural types in short oligomers. 1H CRAMPS spectra are similar to 13C CPMAS in the information obtained, but the resolution is not as good. Using 13C CPMAS, the conformation of polyglycine was investigated in detail. Precipitation from solvents such as DCA or TFA resulted in the rippled beta-sheet structure (PG I), while 3(1)-helix (PG II) was formed by precipitation from aqueous solutions of LiBr. Grinding the sample resulted in an increase in the amount of PG I, indicating that this form is more stable in the solid state. These results agree with previous work on poly(L-alanine) showing that the beta-sheet form is more stable in the solid state. Homopolypeptides with larger side chains did not change conformation upon grinding due to the greater difficulty in disrupting van der Waals interactions and inertia of the large side chains.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0926-2040
pubmed:author
pubmed:issnType
Print
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
94-109
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Determination of the conformation and stability of simple homopolypeptides using solid-state NMR.
pubmed:affiliation
Department of Chemistry, 930 North University Avenue, University of Michigan, Ann Arbor, MI 48109-1055, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't, Evaluation Studies