Studies on Plant Calmodulin and Its Interaction with Antagonist W_7 by Lin~3+ Luminescence Probes

摘要

Plant calmodulin (CaM) has been extracted form cauliflower, and the purified CaM has been identified with the activation of NAD kinase(NADK) and the inhibition effect of CaM antagonist W_7.CaM's intrinsic fluorescence and Tb~3+ fluorescence showed that there was one ty- rosine residue and four metal-binding sites in cauliflower CaM. Based on Forster-type nonradiative energy theory, the distances of Tyr→Ⅲ, Ⅳ has been determined, and these are 1.23 nm (Tyr→site Ⅲ) and 1.18 nm(Tyr→Ⅳ). The Eu~3+ and Tb~3+ fluorescence probes showed that the combination of CaM with W_7 resulted in significant change on CaM's conformation, but did not affect coordination environment of metal-binding sites.