113Cd-NMR evidence for cooperative interaction between amino- and carboxyl-terminal domains of calmodulin.
113Cd-NMR experiments were performed to characterize the nature of Cd2+ binding to calmodulin in the presence of a tetradecapeptide mastoparan or a 26-residue peptide M13 (calmodulin-binding region of skeletal muscle myosin light-chain kinase). The results indicate that binding of these peptides to calmodulin induces a positive cooperativity between Ca2+ binding to C- and N-terminal domains. The results imply that the activation of myosin light-chain kinase caused by the increase in Ca2+ concentration occurs as a result of cooperative interactions not only between two Ca2+ binding sites in each domain but also between the two domains. The interdomain interaction manifests itself only in the presence of such peptides.
Ikura
M
M
High-Resolution Nuclear Magnetic Resonance Laboratory, Hokkaido University, Sapporo, Japan.
Hasegawa
N
N
Aimoto
S
S
Yazawa
M
M
Yagi
K
K
Hikichi
K
K
D000818:Animals; D002104:Cadmium / Q000494:pharmacology*; D002147:Calmodulin / Q000302:isolation & purification / Q000378:metabolism*; D007554:Isotopes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008974:Mollusca; D011487:Protein Conformation; D013737:Testis
D002147:Calmodulin; D007554:Isotopes; D002104:Cadmium