Biological effects of rare earth protein complexes: Influence of lanthanide ions Eu3+, Tb3+ on secondary structure of calmodulins

The secondary structure of four kinds of calmodulins (CaMs; i.e., Brassica campestris pollen CaM, bovine brain CaM, earthworm calcium binding protein, and earthworm new calcium binding protein) in thin films are determined by the FTIR resolution enhanced technique and curve fitting. The variation in the secondary structure of CaM upon its binding with Ca2+, Eu3+, and Tb3+, the assay of phosphodiesterase enzyme, and sodium dodecyl sulfate-polyacry lamide gel electrophoresis are also investigated. The effect of lanthanide ions on the conformation of CaM are described. (C) 1999 John Wiley & Sons, Inc.