(Solved): Patients treated with Gleevec sometimes develop resistance to the drug, causing a reoccurrence o ...

Patients treated with Gleevec sometimes develop resistance to the drug, causing a reoccurrence of chronic myelogenous leukemia. Here, a Threonine at position 315 in the ATP binding pocket of the overactive \( B C R-A B L \) kinase is mutated to Isoleucine in the cancerous cells. Using the structures of Threonine and Isoleucine shown above, how could this mutation cause the drug to stop working in these patients? Mutating Threonine to Isoleucine increases the size of the ATP binding pocket, allowing Gleevec more access to this site. Mutating Threonine to Isoleucine decreases the size of the ATP binding pocket, preventing Gleevec from accessing this site. Mutating Threonine to Isoleucine makes the ATP binding pocket more hydrophilic, weakening the interaction with Gleevec at this site. Mutating Threonine to Isoleucine increases the size of the ATP binding pocket, allowing Gleevec more access to this site. Mutating Threonine to Isoleucine decreases the size of the ATP binding pocket, preventing Gleevec from accessing this site. Mutating Threonine to Isoleucine makes the ATP binding pocket more hydrophilic, weakening the interaction with Gleevec at this site. Mutating Threonine to Isoleucine removes a Van der Waal interaction that stabilized the binding of Gleevec at this site.