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Indian Journal of Chemistry -Section A (IJC-A) >
IJC-A Vol.50A [2011] >
IJC-A Vol.50A(03-04) [March-April 2011] >
| Title: | Structural basis for preferential Ca2+-displacement by a paramagnetic ion (Ce3+) in non-myristoylated neuronal calcium sensor-1 |
| Authors: | Chandra, Kousik
Susmitha, A L
Sharma, Y
Chary, K V R |
| Keywords: | Bioinorganic chemistry
Sensors
Neuronal calcium sensor
Calcium displacement
Cerium |
| Issue Date: | Mar-2011 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | We have
investigated the Ca2+-displacement by a trivalent lanthanide ion (Ce3+)
in a Ca2+-sensor protein called neuronal calcium sensor-1 in its
non-myristoylated form by NMR. We observe that all the Ca2+ bound to
the three active Ca2+-binding loops are displaced by Ce3+.
Microscopically, NMR paramagnetic titration data on [Ca2+]-non-myr-NCS-1
shows that the Ce3+ displaces Ca2+ first from both sites,
EF2 and EF3, almost in parallel, followed by the displacement from EF4. Between
EF2 and EF3, the NMR data conclusively shows that the Ca2+-displacement
is more prominent in EF2 as compared to that in EF3. These findings have been
attributed to: (i) the presence of a higher number of negatively charged
residues in EF2 compared to EF3 and EF4, and, (ii) the presence of a Lys
instead of a highly conserved Phe at –4 position in the first Ca2+-binding
loop, which results in a relatively more open conformation of the N-terminal
domain compared to the C-terminal counterpart. |
| Page(s): | 539-547 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-0975(Online); 0376-4710(Print) |
| Source: | IJC-A Vol.50A(03-04) [March-April 2011]
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