Linked Life Data

2009354

Source:http://linkedlifedata.com/resource/pubmed/id/2009354

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-5-7
pubmed:abstractText
For the first time, conformational relaxation processes have been measured in a small protein, mesoporphyrin-horseradish peroxidase via their influence on spectral diffusion broadening of holes burnt in the fluorescence excitation spectrum of free base mesoporphyrin. Holes were burnt in three 0----0 bands of different tautomeric forms of the chromophore at 1.5 and 4 K, and the spectral diffusion broadening was measured in temperature cycling experiments between 4 and 30 K. The inhomogeneous linewidth for the tautomeric 0----0 bands was estimated to be 60-70 cm-1; the hole width was found narrow, being in the order of 350 MHz (10(-2) cm-1) at 1.5 K what allowed for an extremely sensitive detection of the conformational changes. Though proteins have many features in common with glasses, the spectral diffusion broadening of photochemical holes under temperature cycling conditions in mesoporphyrin horseradish peroxidase has a very different pattern as a function of temperature. Up to 12 K, the linewidth did not significantly change, then around 14 K; a steplike broadening was observed for all three tautomers, although to a different extent. The total magnitude of line broadening up to 30 K was large and also different for the tautomers. We argue that the difference between the behavior of this protein and that of glassy matrices originate from finite size effects; the protein may be characterized by a small number of TLS, and their distribution may bear discrete features.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-3495
pubmed:author
pubmed:issnType
Print
pubmed:volume
59
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
305-12
pubmed:dateRevised
2010-9-9
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Conformational relaxation of a low-temperature protein as probed by photochemical hole burning. Horseradish peroxidase.
pubmed:affiliation
Institut für Physikalische Chemie, Johannes Gutenberg-Universität, Mainz, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't