Substrate-Specific Engineering of Amino Acid Dehydrogenase Superfamily for Synthesis of a Variety of Chiral Amines and Amino Acids

Amino acid dehydrogenases (AADHs) are a group of enzymes that catalyze the reversible reductive amination keto acids with ammonia to produce chiral amino using either nicotinamide adenine dinucleotide (NAD+) or phosphate (NADP+) as cofactors. Among them, glutamate dehydrogenase, valine leucine phenylalanine and tryptophan dehydrogenase have been classified superfamily (s-AADHs) by previous researchers because their conserved structures catalytic mechanisms. Owing excellent stereoselectivity, high atom economy, low environmental impact reaction pathway, these extensively engineered break strict substrate specificities for synthesis value-added compounds (chiral acids, amines, alcohols). Substrate specificity engineering s-AADHs mainly focuses on recognition side chain R backbone carboxyl group. This review summarizes reported studies reports this shares hotspots (the inside pocket, anchor sites, entrance tunnel, hinge region), which sheds light substrate-specific tailoring enzymes.