Hydrolysis of AMPPNP by the motor domain of ncd, a kinesin-related protein

AMPPNP was found to be hydrolyzed by the motor domain of ncd (the product of a Drosophila gene, Iron-claret disjunctional), a kinesin-related protein. This hydrolysis could be monitored by P-31 NMR spectroscopy and by an assay of phosphate, one of the products of the hydrolysis. The rate was approximate to 0.00001 s(-1), 1% of the ATP turnover rate, The AMPPNP turnover was not stimulated by microtubules. Kinesin motor domain also turned over AMPPNP but at a somewhat lower rate, Although the turnover was slow, the present finding may present an important caveat, since AMPPNP has been widely used for investigations of kinesin and kinesin-related proteins as a non-hydrolyzable ATP analogue. (C) 1997 Federation of European Biochemical Societies.