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Salt enhances calmodulin-target interaction

André, Ingemar LU orcid ; Kesvatera, Tönu LU ; Jönsson, Bo LU and Linse, Sara LU (2006) In Biophysical Journal 90(8). p.2903-2910
Abstract
Calmodulin (CaM) operates as a Ca2+ sensor and is known to interact with and regulate hundreds of proteins involved in a great many aspects of cellular function. It is of considerable interest to understand the balance of forces in complex formation of CaM with its target proteins. Here we have studied the importance of electrostatic interactions in the complex between CaM and a peptide derived from smooth-muscle myosin light-chain kinase by experimental methods and Monte Carlo simulations of electrostatic interactions. We show by Monte Carlo simulations that, in agreement with experimental data, the binding affinity between CaM and highly charged peptides is surprisingly insensitive to changes in the net charge of both the protein and... (More)
Calmodulin (CaM) operates as a Ca2+ sensor and is known to interact with and regulate hundreds of proteins involved in a great many aspects of cellular function. It is of considerable interest to understand the balance of forces in complex formation of CaM with its target proteins. Here we have studied the importance of electrostatic interactions in the complex between CaM and a peptide derived from smooth-muscle myosin light-chain kinase by experimental methods and Monte Carlo simulations of electrostatic interactions. We show by Monte Carlo simulations that, in agreement with experimental data, the binding affinity between CaM and highly charged peptides is surprisingly insensitive to changes in the net charge of both the protein and peptide. We observe an increase in the binding affinity between oppositely charged partners with increasing salt concentration from zero to 100 mM, showing that formation of globular CaM-kinase type complexes is facilitated at physiological ionic strength. We conclude that ionic interactions in complex formation are optimized at pH and saline similar to the cell environment, which probably overrules the electrostatic repulsion between the negatively charged Ca2+-binding domains of CaM. We propose a conceivable rationalization of CaM electrostatics associated with interdomain repulsion. (Less)
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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Biophysical Journal
volume
90
issue
8
pages
2903 - 2910
publisher
Cell Press
external identifiers
  • wos:000236226900024
  • pmid:16428276
  • scopus:33646186034
ISSN
1542-0086
DOI
10.1529/biophysj.105.068718
language
English
LU publication?
yes
additional info
The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Biophysical Chemistry (LTH) (011001011), Theoretical Chemistry (S) (011001039)
id
5e62e0d2-a0df-4e27-86c1-bdc2723d6042 (old id 415231)
date added to LUP
2016-04-01 12:07:21
date last changed
2021-09-22 05:31:05
@article{5e62e0d2-a0df-4e27-86c1-bdc2723d6042,
  abstract     = {Calmodulin (CaM) operates as a Ca2+ sensor and is known to interact with and regulate hundreds of proteins involved in a great many aspects of cellular function. It is of considerable interest to understand the balance of forces in complex formation of CaM with its target proteins. Here we have studied the importance of electrostatic interactions in the complex between CaM and a peptide derived from smooth-muscle myosin light-chain kinase by experimental methods and Monte Carlo simulations of electrostatic interactions. We show by Monte Carlo simulations that, in agreement with experimental data, the binding affinity between CaM and highly charged peptides is surprisingly insensitive to changes in the net charge of both the protein and peptide. We observe an increase in the binding affinity between oppositely charged partners with increasing salt concentration from zero to 100 mM, showing that formation of globular CaM-kinase type complexes is facilitated at physiological ionic strength. We conclude that ionic interactions in complex formation are optimized at pH and saline similar to the cell environment, which probably overrules the electrostatic repulsion between the negatively charged Ca2+-binding domains of CaM. We propose a conceivable rationalization of CaM electrostatics associated with interdomain repulsion.},
  author       = {André, Ingemar and Kesvatera, Tönu and Jönsson, Bo and Linse, Sara},
  issn         = {1542-0086},
  language     = {eng},
  number       = {8},
  pages        = {2903--2910},
  publisher    = {Cell Press},
  series       = {Biophysical Journal},
  title        = {Salt enhances calmodulin-target interaction},
  url          = {http://dx.doi.org/10.1529/biophysj.105.068718},
  doi          = {10.1529/biophysj.105.068718},
  volume       = {90},
  year         = {2006},
}