Natively unfolded C-terminal domain of caldesmon remains substantially unstructured after the effective binding to calmodulin
Article first published online: 12 SEP 2003
Copyright © 2003 Wiley-Liss, Inc.
Proteins: Structure, Function, and Bioinformatics
Volume 53, Issue 4, pages 855–n/a, 1 December 2003
How to Cite
Permyakov, S. E., Millett, I. S., Doniach, S., Permyakov, E. A. and Uversky, V. N. (2003), Natively unfolded C-terminal domain of caldesmon remains substantially unstructured after the effective binding to calmodulin. Proteins, 53: 855–n/a. doi: 10.1002/prot.10481
- Issue published online: 17 NOV 2003
- Article first published online: 12 SEP 2003
- Manuscript Accepted: 31 MAR 2003
- Manuscript Revised: 28 MAR 2003
- Manuscript Received: 15 JAN 2003
- INTAS. Grant Number: 01-2347 CA
- natively unfolded protein;
- intrinsically unstructured protein
The structure of C-terminal domain (CaD136, C-terminal residues 636–771) of chicken gizzard caldesmon has been analyzed by a variety of physico-chemical methods. We are showing here that CaD136 does not have globular structure, has low secondary structure content, is essentially noncompact, as it follows from high Rg and RS values, and is characterized by the absence of distinct heat absorption peaks, i.e. it belongs to the family of natively unfolded (or intrinsically unstructured) proteins. Surprisingly, effective binding of single calmodulin molecule (Kd = 1.4 ± 0.2 μM) leads only to a very moderate folding of this protein and CaD136 remains substantially unfolded within its tight complex with calmodulin. The biological significance of these observations is discussed. Proteins 2003. © 2003 Wiley-Liss, Inc.