Formating chemical equations for proteins binding in multiple configurations

I am working on problems involving protein-protein binding, particularly ones in which two proteins may bind in two or more configurations, and where some of the resultant structures may also bind with other proteins subsequently, and I am wondering how best to format chemical equations.


I am used to writing chemical equations on a single line like:


$$\ce{[A] + [B] <=>[k\_\mathrm{a}][k\_\mathrm{d}] [AB]} \tag{1}$$


but formating a reaction where multiple dimers can arise from the same reaction on a single line looks confusing and ugly:


$$\ce{[AB]\_1 <=>[k\_\mathrm{d1}][k\_\mathrm{a1}] [A] + [B] <=>[k\_\mathrm{a2}][k\_\mathrm{d2}] [AB]\_2} \tag{2}$$


Worse than that, its not clear how one would write an equation where a third configuration could emerge from the reaction. 


What is the best way to format equations like this? 


