Prediction of the GTPase activities by using the semiempirical molecular orbital theory

Assuming that substrate-assisted catalysis is the mechanism of GTP hydrolysis for ras p21 and other GTP-binding proteins, 1) we used the PM3 semiempirical molecular orbital method to predict from the calculated reaction profiles of GTP hydrolysis reactions the changes in GTPase activities caused by mutations. We succeeded in making qualitative predictions for mutants.