Formation and Characterization of Kinesin•ADP•Fluorometal Complexes

抄録

Recent crystallographic studies of motor proteins showed that the structure of the motor domains of myosin and kinesin are highly conserved. Thus, these motor proteins, which are important for motility, may share a common mechanism for generating energy from ATP hydrolysis. We have previously demonstrated that, in the presence of ADP, myosin forms stable ternary complexes with new phosphate analogues of aluminum fluoride (AlF₄^-) and beryllium fluoride (BeF_n), and these stable complexes mimic the transient state along the ATPase kinetic pathway [Maruta et al. (1993) J. Biol. Chem. 268, 7093-7100]. In this study, we examined the formation of kinesin. ADP. fluorometals ternary complexes and analyzed their characteristics using the fluorescent ATP analogue NBD-ATP (2'(3')-O-[6-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl)amino)hexanoyl]-ADP). Our results suggest that these ternary complexes may mimic transient state intermediates in the kinesin ATPase cycle. Thus, the kinesin. ADP. AlF₄- complex resembles the kinesin-ADP state, and the kinesin. ADP. BeF_n complex mimics the kinesin. ADP. P_i state.