Magnetism does not play a role in binding in biology. The primary determinants of binding are: shape complementarity, electrostatic interactions, van der waals

Magnetism does not play a role in binding in biology. The primary determinants of binding are: shape complementarity, electrostatic interactions, van der waals forces, and some amount of hard to explain entropy. (biomagnetism is a thing, but I'm not aware of any cases where binding occurs due to magnetic forces)