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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-11-3
pubmed:abstractText
We present an improved technique for estimating protein secondary structure content from amide I and amide III band infrared spectra. This technique combines the superposition of reference spectra of pure secondary structure elements with simultaneous aromatic side chain, water vapor, and solvent background subtraction. Previous attempts to generate structural reference spectra from a basis set of reference protein spectra have had limited success because of inaccuracies arising from sequential background subtractions and spectral normalization, arbitrary spectral band truncation, and attempted resolution of spectroscopically degenerate structure classes. We eliminated these inaccuracies by defining a single mathematical function for protein spectra, permitting all subtractions, normalizations, and amide band deconvolution steps to be performed simultaneously using a single optimization algorithm. This approach circumvents many of the problems associated with the sequential nature of previous methods, especially with regard to removing the subjectivity involved in each processing step. A key element of this technique was the calculation of reference spectra for ordered helix, unordered helix, sheet, turns, and unordered structures from a basis set of spectra of well-characterized proteins. Structural reference spectra were generated in the amide I and amide III bands, both of which have been shown to be sensitive to protein secondary structure content. We accurately account for overlaps between amide and nonamide regions and allow different structure types to have different extinction coefficients. The agreement between our structure estimates, for proteins both inside and outside the basis set, and the corresponding determinations from X-ray crystallography is good.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0003-2697
pubmed:author
pubmed:copyrightInfo
Copyright 2000 Academic Press.
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
285
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
33-49
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
A holistic approach for protein secondary structure estimation from infrared spectra in H(2)O solutions.
pubmed:affiliation
Applied Biophysics Laboratory, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.