Question 14 Studying bes To study motor function on microtubules scientists can create purified stable fluorescently labeled microtubules and motors different colors and watch movement of the kinesin walking along the microtubule using a fluorescence microscopy This allows scientists to analyze the kinetics of kinesin movement velocity of movement what regulates movement etc A How might you expect that molecular biologists create stable and labeled microtubules for this experiment To create stable and labeled microtubules for this experiment they would likely polymerize purified tubulin into microtubules in the presence of a fluorescent marker or dye The addition of a stabilizing agent like taxol can help block the microtubules dynamic instability and promote stability B Based on what you know about how kinesin motor activity is regulated by ATP ADP and nucleotide release what do you think would happen if you added only ADP to this experiment rather than ATP Would the kinesin ever bind the MT Would you observe the kinesin walking on the microtubule The movie 17 7 in the movies folder in Moodle might be helpful for this question Bio285 F23 If you only added ADP rather than ATP to this experiment the kinesin would bind to the microtubule because ADP bound kinesio has a good affinity for the microtubule That would cause a conformational change leading to ADP dissociating from the binding pocket Since there s no ATP to diffuse into the binding pocket of kinesio and cause the neck linker to change conformation and cause walking kinesin would bind to ADP and remain bound to ADP and therefore bound to the microtubule and no walking is observed C Based on what you know about how kipesin motor activity is regulated what do you think would happen if you added a n00 hdolzable ATP analog to this experiment Would the kinesin ever bind the MT Would you observe the kinesin walking on the microtubule Here is a structure of an example 000 bydrolyzable ATP analog ATP y S S 0 O P P P NH Topic 6 Problem Set Answer Key N O Francis N N