KChIP3: a binding protein for Taiwan banded krait beta-bungarotoxin.
Using B1 chain of beta-bungarotoxin (beta-Bgt) as bait in yeast two-hybrid screen, we found that KChIP3 was a binding protein of B1 chain. Thus, protein-protein interaction between beta-Bgt and KChIP3 is investigated in the present study. Pull-down assay showed that recombinant KChIP3 proteins were associated with beta-Bgt as well as B1 chain, whereas the inability of KChIPs 1, 2 and 4 to bind with beta-Bgt was observed. Although Ca2+ was not a crucial factor essential for the binding of KChIP3 with beta-Bgt and B1 chain, their interaction could be enhanced by the addition of Ca2+. Alternatively, the association of A1 chain of beta-Bgt with KChIP3 was marginally detected. The dissociation constant of beta-Bgt with KChIP3 were 12.2 and 6.08 microM in the absence and presence of 2mM Ca2+, respectively. Moreover, native KChIP3 from rat brain was to be isolated by beta-Bgt-Sepharose. These observations indicate that KChIP3 is a binding protein of beta-Bgt. In view of the multiple functions of KChIP3 in neuronal cells, the interaction of KChIP3 with beta-Bgt may represent an event for the manifestation of the biological activities of beta-Bgt.
Lin
Ya-Ling
YL
Institute of Biomedical Sciences, National Sun Yat-Sen University, Number 70, Lien-Hai Road, Kaohsiung 80424, Taiwan, ROC.
Wu
Pei-Fung
PF
Wu
Tony T
TT
Chang
Long-Sen
LS
D000818:Animals; D001665:Binding Sites; D002038:Bungarotoxins / Q000378:metabolism*; D017838:Bungarus; D017931:DNA Primers; D005260:Female; D006801:Humans; D051605:Kv Channel-Interacting Proteins / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000378:metabolism
D002038:Bungarotoxins; D017931:DNA Primers; D051605:Kv Channel-Interacting Proteins; D011994:Recombinant Proteins