Binding affinities and activation of Asp712Ala and Cys100Ser mutated kinin B1 receptor forms suggest a bimodal scheme for the molecule of bound-DABK

► The N-terminal segment of DBK binds to extracellular site as EC3 loop of BKRB1. ► The lack of second disulfide bond of BKRB1 leads to a weak agonist binding. ► Interaction between DBK and BKRB1 follows the same bimodal pattern of AngII and AGTR1.