First Author | Gangopadhyay JP | Year | 2004 |
Journal | Biochem Biophys Res Commun | Volume | 323 |
Issue | 3 | Pages | 760-8 |
PubMed ID | 15381065 | Mgi Jnum | J:92846 |
Mgi Id | MGI:3054605 | Doi | 10.1016/j.bbrc.2004.08.154 |
Citation | Gangopadhyay JP, et al. (2004) Fluorescence probe study of Ca(2+)-dependent interactions of calmodulin with calmodulin-binding peptides of the ryanodine receptor. Biochem Biophys Res Commun 323(3):760-8 |
abstractText | We have used a highly environment-sensitive fluorescent probe 6-bromoacetyl-2-dimethylaminonaphthalene (badan) to study the interaction between calmodulin (CaM) and a CaM-binding peptide of the ryanodine receptor (CaMBP) and its sub-fragments F1 and F4. Badan was attached to the Thr34Cys mutant of CaM (CaM-badan). Ca(2+) increase in a physiological range of Ca(2+) (0.1-2microM) produced about 40 times increase in the badan fluorescence. Upon binding to CaMBP, the badan fluorescence of apo-CaM showed a small increase at a slow rate; whereas that of Ca-CaM showed a large decrease at a very fast rate. Upon binding of CaM to the badan-labeled CaMBP, the badan fluorescence showed a small and slow increase at low Ca(2+), and a large and fast increase at high Ca(2+). Thus, the badan probe attached to CaM Cys(34) can be used to monitor conformational changes occurring not only in CaM, but also those in the CaM-CaMBP interface. Based on our results we propose that both the interaction interface and the global conformation of the CaM-CaMBP complex are altered by calcium. |