A method for producing a chiral amine may include performing a transamination reaction of a prochiral amino acceptor and an amino donor in a first solution in the presence of a transaminase, thereby forming a chiral amine and a co-product in the first solution. The amino donor is a high molecular weight (HMW) amino donor. In some examples, the molecular weight of the HMW amino donor is at least 150 g/mol. In some examples, the amino donor is affixed on a support, the total molecular weight of the amino donor and the support being at least 150 g/mol.