Linked Life Data

3888265

Source:http://linkedlifedata.com/resource/pubmed/id/3888265

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1985-6-26
pubmed:abstractText
We have produced T4 lysozyme using a bacterial expression system which allows efficient incorporation of isotopically labeled amino acids in lysozyme. By using conditions that repress the expression of various transaminases, we have incorporated 15N-labeled amino acid into the five phenylalanine residues of the protein. The relatively large spin--spin coupling (87 +/- 3 Hz) between the 15N nucleus and the phenylalanine amide protons may then be exploited in a variety of ways to selectively observe the five phenylalanine amide proton resonances. These include a simple "echo difference" technique which displays the amide proton resonances in one dimension and a "forbidden echo" technique [Bax, A., Griffey, R. H., & Hawkins, B.L. (1983) J. Magn. Reson. 55, 301-335] which gives two-dimensional information allowing the proton and 15N chemical shifts of each amide to be determined. With these approaches, all five phenylalanine amide protons give resolved resonances. Deuterium exchange experiments demonstrate that three of the five resonances are slow to exchange (half-times of about 1 week at pH 5.5 and 4 degrees C) while the other two are rapid with complete exchange in hours or less. These observations correlate well with the secondary structure of the protein which shows three residues in alpha-helical regions and two residues in surface-exposed environments. This approach of isotopic substitution on nitrogen or carbon atoms is of general utility and should allow virtually any proton on a protein of molecular weight 20 000 or thereabout to be selectively observed.
pubmed:grant
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
12
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
817-22
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Nuclear magnetic resonance observation and dynamics of specific amide protons in T4 lysozyme.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.