[6][13] This domain contains residues that interact with the active site of the neighboring subunit to facilitate substrate and cofactor binding.

Additionally, residues neighboring the pyridine nitrogen in PLP help stabilize its positive charge, thereby increasing its electrophilic character.

These stacking interactions between PLP and aromatic side chains can be found in most PLP-dependent enzymes as it plays an important role in catalyzing the reaction by facilitating transaldimination.

[13] Given that the pH optimum for the enzyme is between 8.0 and 9.0, a tyrosine residue in the catalytic pocket exists as a phenolate, which abstracts a proton from the α-amino group of the substrate.

The released lysine can now abstract the proton from the Cα and form a quinoid intermediate, which is facilitated by the delocalization of the negative charge over PLP's conjugated p-system.

[14] Subsequently, the protonation of Sγ induces Cβ-Sγ bond cleavage, thereby releasing homocysteine[3][13] The external aldimine is displaced by the nucleophilic attack of the lysine, regenerating the catalytically active internal aldimine and releasing dehydroalanine.

[4] Lastly, the enamine tautomerizes into an imine that undergoes hydrolytic deamination to form pyruvate and ammonia.

It is believed that the inhibitor binds to the enzyme in a similar way as the substrate; however, after the abstraction of the α-proton, the reaction proceeds to create an inactive ketimine PLP derivative.

Further research is needed to characterize the full extent cystathionine beta-lyase inhibition has on microbial and fungal growth.