ine ▁re upt ake ▁in hib itors ▁bind ▁to ▁the ▁dop am ine ▁trans porter ▁substr ate ▁recognition ▁site ▁at ▁T m ▁lo ci ▁ 1 , ▁ 7 ▁& ▁ 1 0 — 1 2 ; ▁whereas ▁c oca ine ▁& ▁m eth yl phen id ate ▁similarly ▁share ▁the ▁ 1 ▁& ▁ 7 ▁places , ▁but ▁diver ge ▁from ▁the ▁usual ▁lig and ▁site ▁of ▁the ▁latter ▁and ▁instead ▁coh ab it ▁the ▁ 9 — 1 1 ▁lo ci . ▁Site - direct ed ▁mut agen esis ▁techniques ▁have ▁el uc id ated ▁that ▁the ▁hydro ph ob ic ▁put ative ▁transm emb rane ▁regions ▁at ▁one ▁& ▁seven ▁contain ▁as part ate ▁and ▁ser ine ▁resid ues , ▁and ▁that ▁the ▁car box yl - group ▁interact s ▁with ▁the ▁former ▁as part ic ▁acid ▁resid ue ▁ 7 9 ▁which ▁eng ages ▁with ▁c oca ine ▁& ▁m eth yl phen id ate ' s ▁pro ton ated ▁nit ro gen ▁at ▁the ▁trans porter . ▁Pre vious ▁theories ▁of ▁an ▁al loster ic ▁site ▁for ▁c oca ine ▁and ▁related ▁comp ounds ▁which ▁do ▁not ▁overlap ▁with ▁the ▁binding ▁site ▁of ▁dop am ine ▁itself ▁are ▁less ▁pre val ent ▁in ▁light ▁of ▁more ▁recent ▁observations ▁since ▁Le u T ▁became ▁feas ible ▁as ▁a ▁model ing ▁template . ▁ ▁One ▁r ationale ▁to ▁denote ▁the ▁subject ive ▁preference ▁for ▁c oca ine ▁over ▁m eth yl phen id ate ▁in ▁animal ▁hab itu ation ▁&