Linked Life Data

2166598

Source:http://linkedlifedata.com/resource/pubmed/id/2166598

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-9-20
pubmed:abstractText
The Ca2(+)-ATPase in native sarcoplasmic reticulum membranes was selectively spin-labeled for saturation transfer electron spin resonance (ESR) studies by prelabeling with N-ethylmaleimide and by using low label/protein ratios. Results with the nitroxide derivative of the standard sulphydryl-modifying reagent, maleimide, were compared with a series of six novel nitroxide beta-substituted vinyl aryl ketone derivatives which differed (with two exceptions) in the substituent at the ketone position. The two exceptions had a different electron withdrawing group at the alpha-carbon, to enhance further the electrophilic character of the beta-carbon. Although differing in their reactivity, all the conjugated unsaturated ketone nitroxide derivatives displayed saturation transfer ESR spectra indicative of much slower motion than did the maleimide derivative. The saturation transfer ESR spectra of maleimide-labeled Ca2(+)-ATPase therefore most likely contain substantial contributions from segmental motion of the labeled group. The effects of the level of spin labeling were also investigated. With increasing degree of spin label incorporation, the linewidths of the conventional ESR spectrum progressively increased and the intensity of the saturation transfer spectrum dropped dramatically, as a result of increasing spin-spin interactions. The hyperfine splittings of the conventional spectrum and the outer lineheight ratios of the saturation transfer spectrum remained relatively unchanged. Extrapolation back to zero labeling level yielded comparable values for the effective rotational correlation times deduced from the saturation transfer spectrum intensities and from the lineheight ratios, for the vinyl ketone label. For the maleimide label the extrapolated values from the integral are significantly lower than those from the lineheight ratios, probably because of the segmental motion. Comparison is made of the effective rotational correlation time for the vinyl ketone label with the predictions of hydrodynamic models for the protein diffusion, in a discussion of the aggregation state of the Ca2(+)-ATPase in the native sarcoplasmic reticulum membrane. The implications for the study of protein rotational diffusion and segmental motion, and of the proximity relationships between labeled groups, using saturation transfer ESR spectroscopy are discussed.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-134038, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-14907713, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-200229, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-207310, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-214789, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-2436519, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-2536556, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-2820492, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-2831948, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-2837478, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-2931429, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-2936737, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-2953711, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-2957170, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-2993904, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-3006752, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-3013330, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-3013331, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-3021193, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-3816699, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-4345088, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-4908377, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-6216914, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-6222773, http://linkedlifedata.com/resource/pubmed/commentcorrection/2166598-7284552
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-3495
pubmed:author
pubmed:issnType
Print
pubmed:volume
58
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
231-41
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Saturation transfer electron spin resonance of Ca2(+)-ATPase covalently spin-labeled with beta-substituted vinyl ketone- and maleimide-nitroxide derivatives. Effects of segmental motion and labeling levels.
pubmed:affiliation
Abteilung Spektroskopie, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't