Abstract
Although the 3D structure of the Ca2+-bound CaM (Ca2+/CaM) complex with the antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulphonamide (W-7), has been resolved, the dynamic changes in Ca2+/CaM structure upon interaction with W-7 are still unknown. We investigated time- and temperature-dependent dynamic changes in Ca2+/CaM interaction with W-7 in physiological conditions using one- and two-dimensional Fourier-transformed infrared spectroscopy (2D-IR). We observed changes in the α-helix secondary structure of Ca2+/CaM when complexed with W-7 at a molar ratio of 1:2, but not at higher molar ratios (between 1:2 and 1:5). Kinetic studies revealed that, during the initial 125s at 25°C, Ca2+/CaM underwent formation of secondary coil and turn structures upon binding to W-7. Variations in temperature that induced significant changes in the structure of the Ca2+/CaM complex failed to do so when Ca2+/CaM was complexed with W-7. We concluded that W-7 induced stepwise conformational changes in Ca2+/CaM that resulted in a rigidification of the complex and its inability to interact with target proteins and/or polypeptides.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Biochemical and Biophysical Research Communications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
