Linked Life Data

427100

Source:http://linkedlifedata.com/resource/pubmed/id/427100

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1979-6-29
pubmed:abstractText
To probe the details of small amplitude motions in proteins, a dynamical analysis of the orientation fluctuations of two tyrosine side chains in the bovine pancreatic trypsin inhibitor is presented. Detailed results are given for the time history and correlation functions obtained for the ring motion from a molecular dynamics simulation of the entire protein. It is shown that even on a picosecond time scale orientational fluctuations of +/-30 degrees from the average position occur for the tyrosine rings in the interior of the protein. It is found that the Langevin equation is applicable to the ring torsional motion, which corresponds to that of an angular harmonic oscillator with near-critical damping. Two possible microscopic models for the observed damping effects are outlined. One of these, analogous to liquid behavior, is based on kinetic theory and takes account of the collisions which occur between atoms of the protein; the other, more analogous to solid behavior, involves the coupling among a large number of harmonic oscillators. The collisional model with parameters obtained from theoretical estimates leads to good agreement with the correlation functions from the dynamic simulation. However, the dephasing of harmonic oscillations can yield similar short-time results so that a distinction between the two models is difficult. The importance of damping effects on the motions involved in conformational transitions and enzymatic reactions is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
927-42
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1979
pubmed:articleTitle
Picosecond dynamics of tyrosine side chains in proteins.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.