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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
3
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pubmed:dateCreated |
1979-7-25
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pubmed:abstractText |
The effects of pH and Ca2+ on the intrinsic fluorescence of bovine prothrombin fragment 1 were investigated to deduce the nature of protein functional groups involved in Ca2+ binding to fragment 1. From pH values of 9 to 3, increasing the H3O+ concentration results in quenching of the fluorescence of fragment 1. Reversible pH-titration curves are obtained which appear to consist of two regions. From pH 4 to pH6.5 a broad titration curve is obtained, whereas from pH6.5 to 9 a more pronounced titration behaviour is evidenced by a group or groups on fragment 1 with an apparent pKa of approx. 7.5. In contrast, the apparent association constant for Ca2+ and fragment 1 shows a sharp pH-dependence in the region between pH7 and 8 with tighter Ca2+ binding at higher pH values. A PKa of approx. 7.5 can be estimated for the group or groups on fragment 1 linked to the tight binding of Ca2+. Both H3O+ and Ca2+ result in blue-shifts in the wave-lengths of fragment-1 emission. These results are interpreted in terms of H+ - and Ca2+ - induced changes in the conformation of fragment 1 as a result of surface-charge neutralization.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-1011988,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-1117001,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-1126944,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-1164027,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-1170888,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-14220741,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-345049,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-4514304,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-5893637,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-812,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-838700,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-863726,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-870030,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-965381,
http://linkedlifedata.com/resource/pubmed/commentcorrection/36074-993198
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0264-6021
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
177
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
879-86
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
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pubmed:year |
1979
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pubmed:articleTitle |
The effects of calcium ions and pH on bovine prothrombin fragment 1. Intrinsic fluroescence studies.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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