I was wondering if the ability to make a "coagulated protein mass" was unique to gluten in wheat. For example, if one grinds up a bunch of lentils into a very fine powder and then adds water to make a lentil dough (And stirring consistently in one direction to bind proteins) is it possible to wash away the starch and leave behind a lentil-protein mass? If not lentils then which sorts of seeds/nuts/vegetables are amenable to this "seitanification" process? 
The important part isn’t (just) coagulation, but the viscoelasticity (pliant stretchiness) which allows it to form a loose structure incorporating starch and gas. Few proteins have that property. (Casein, a milk protein, comes to mind; the process of making mozzarella is not so very different from that of making seitan.) If there was a legume-derived protein with largely the same properties as gluten, you definitely would have heard about it by now. 