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Modulating the affinity and the selectivity of engineered calmodulin EF‐Hand peptides for lanthanides
Author(s) -
Clainche Loïc Le,
Figuet Mélanie,
MontjardetBas Véronique,
Blanchard Sébastien,
Vita Claudio
Publication year - 2006
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.20946
Subject(s) - chemistry , calmodulin , ef hand , lanthanide , peptide , stereochemistry , terbium , amino acid , dissociation constant , binding site , combinatorial chemistry , biochemistry , receptor , enzyme , organic chemistry , ion
A set of engineered peptides (33 amino acids long) corresponding to the helix‐turn‐helix (EF‐Hand) motif of the metal‐binding site I of the protein calmodulin from paramecium tetraurelia have been synthesized. A disulfide bridge has been introduced in the native sequence in order to stabilize a native‐like conformation. The calcium‐binding carboxylate residues in positions 20, 22, 24, and 31 were mutated into other amino acids and the influence of such mutations on the binding affinity of the peptides for calcium and lanthanides have been studied. It was shown that the binding affinity for terbium ions can be modulated with dissociation constants ranging from 40 nmolar to 40 mmolar. The study of the influence of the mutations on the terbium affinity showed that the residue in position 24 played a key role on the capability of the peptides to bind lanthanides and that the affinity could be enhanced by mutations on non‐coordinating positions. Such peptides with high affinity for lanthanides may facilitate the development of new highly sensitive biosensors to monitor the metal pollution in the environment. © 2006 Wiley Periodicals, Inc.