Linked Life Data

15568803

Source:http://linkedlifedata.com/resource/pubmed/id/15568803

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
48
pubmed:dateCreated
2004-11-30
pubmed:abstractText
Flavodoxins (Flds) are electron transfer proteins that carry a noncovalently bound flavin mononucleotide molecule (FMN) as a redox active center. A distinguishing feature of these flavoproteins is the dramatic change in the E(sq/rd) reduction potential of the FMN upon binding to the apoprotein (at pH 8.0, from -269 mV when free in solution to -438 mV in Anabaena Fld). In this study, the contribution of three neighboring FMN residues, Thr56, Asn58, and Asn97, and of three negatively charged surface residues, Glu20, Asp65, and Asp96, to modulate the redox properties of FMN upon its binding to the apoprotein has been investigated. Additionally, the role of these residues in the apoflavodoxin:FMN interaction has been analyzed. Concerning the redox potentials, the most noticeable result was obtained for the Thr56Gly mutant. In this Fld variant, the increased accessibility of FMN leads to an increase of +63 mV in the E(sq/rd) value. On the other hand, a correlation between the electrostatic environment of FMN and the E(sq/rd) has been observed. The more positive residues or the less negative residues present in the surroundings of the FMN N(1) atom, then the less negative the value for E(sq/rd). With regard to FMN binding to apoflavodoxin, breaking of hydrophobic interactions between FMN and residues 56, 58, and 97 seems to increase the K(d) values, especially in the Thr56Gly Fld. Such results suggest that the H-bond network in the FMN environment influences the FMN affinity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15111-21
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Role of neighboring FMN side chains in the modulation of flavin reduction potentials and in the energetics of the FMN:apoprotein interaction in Anabaena flavodoxin.
pubmed:affiliation
Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias and Institute of Biocomputation and Physics of Complex Systems (BIFI), Universidad de Zaragoza, 50009-Zaragoza, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't