NBC is dependent on pH_i and pH_e, 
J_kinetic is scaled by (1+10^(ni(pH_i-pKi)))*(1+10^(-ne(pH_e-pKe)))
This scale is rearranged to 
scale = (1+Kmi^ni*[H_i]^-ni)*(1+Kme^-ne*[H_e]^ne)

You can loosely interpret this as 
1 values are neglected
Km values just change the rxn speed
-ni and ne are the stoichiometries of H_i and H_e

So -ni.[H_i] and ne.[H_e] interpreted to affect both forward and reverse rate constants for every reaction in bond graph NBC transporter.