Linked Life Data

11306109

Source:http://linkedlifedata.com/resource/pubmed/id/11306109

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-3
pubmed:dateCreated
2001-4-18
pubmed:abstractText
The beta-subunit of the voltage-sensitive K(+) channels shares 15-30% amino acid identity with the sequences of aldo-keto reductases (AKR) genes. However, the AKR properties of the protein remain unknown. To begin to understand its oxidoreductase properties, we examine the pyridine coenzyme binding activity of the protein in vitro. The cDNA of K(v)beta2.1 from rat brain was subcloned into a prokaryotic expression vector and overexpressed in Escherichia coli. The purified protein was tetrameric in solution as determined by size exclusion chromatography. The protein displayed high affinity binding to NADPH as determined by fluorometric titration. The K(D) values for NADPH of the full-length wild-type protein and the N-terminus deleted protein were 0.1+/-0.007 and 0.05+/-0.006 M, respectively - indicating that the cofactor binding domain is restricted to the C-terminus, and is not drastically affected by the absence of the N-terminus amino acids, which form the ball and chain regulating voltage-dependent inactivation of the alpha-subunit. The protein displayed poor affinity for other coenzymes and the corresponding values of the K(D) for NADH and NAD were between 1-3 microM whereas the K(D) for FAD was >10 microM. However, relatively high affinity binding was observed with 3-acetyl pyridine NADP, indicating selective recognition of the 2' phosphate at the binding site. The selectivity of K(v)beta2.1 for NADPH over NADP may be significant in regulating the K(+) channels as a function of the cellular redox state.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0009-2797
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
130-132
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
955-62
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:11306109-Animals, pubmed-meshheading:11306109-Base Sequence, pubmed-meshheading:11306109-Binding Sites, pubmed-meshheading:11306109-Coenzymes, pubmed-meshheading:11306109-DNA Primers, pubmed-meshheading:11306109-Delayed Rectifier Potassium Channels, pubmed-meshheading:11306109-Escherichia coli, pubmed-meshheading:11306109-Flavin-Adenine Dinucleotide, pubmed-meshheading:11306109-Kinetics, pubmed-meshheading:11306109-NAD, pubmed-meshheading:11306109-NADP, pubmed-meshheading:11306109-Oxidation-Reduction, pubmed-meshheading:11306109-Potassium Channels, pubmed-meshheading:11306109-Potassium Channels, Voltage-Gated, pubmed-meshheading:11306109-Protein Subunits, pubmed-meshheading:11306109-Pyridines, pubmed-meshheading:11306109-Rats, pubmed-meshheading:11306109-Recombinant Proteins
pubmed:year
2001
pubmed:articleTitle
Binding of pyridine coenzymes to the beta-subunit of the voltage sensitive potassium channels.
pubmed:affiliation
Division of Cardiology, Department of Medicine, Jewish Cardiovascular Research Center, University of Louisville, 500, South Floyd Street, 40202, Louisville, KY, USA. siqiliu@louisville.edu
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't