The first step of the LSD1 catalytic reaction is the abstraction of hydride from the methyl of the H3K4 side chain N-methyl by FAD in the oxidized state that generates a stabilized methylene iminium ion.

The overall reaction stoichiometry thus involves the conversion of an N-methyl group by water and oxygen to give molecules of formaldehyde, hydrogen peroxide, and the product N-H terminus.

LSD1 cannot demethylate H3K4 trimethyl (N-tri-methyl-lysine) because the initial iminium species cannot be formed owing to a lack of an available lone electron pair at the N-center, essential for formation of the requisite stabilizing pi-system.

One method to examine the function of the LSD1 protein is to reduced the amount of KDM1A mRNA using a specific silencing RNA, so called siRNA knockdown.

The interaction of LSD1 with the transcription factor GFI1B is particularly important for regulating the balance in stem cells between replication and self-renewal as well as the maturation the megakaryocyte-erythroid progenitors to megakaryocytes.

Indeed, in acute myeloid leukemia (AML), the interaction of LSD1 and GFI1B was definitively demonstrated to be necessary for the proliferation of leukemic initiating cells, while the LSD1 demethylase activity was not essential for this phenotype.

[16][17] As mentioned above, in several cancers, higher levels of expression of LSD1 are correlated with poorer outcomes suggesting LSD1 inhibition could be a part of an anti-neoplastic regimen.

[21] Given LSD1 is critical for the maturation of megakaryocytes, the bone marrow cells that produce platelets, LSD1 is well-suited as a target for the treatment of essential thrombocythemia, an indication currently in development for bomedemstat by Imago BioSciences.