Bisphosphoglycerate Mutase (BPGM)

Bisphosphoglycerate mutase (BPGM) is an enzyme unique to erythrocytes and placental cells. It is responsible for the catalytic synthesis of 2,3-Bisphosphoglycerate (2,3-BPG) from 1,3-bisphosphoglycerate. BPGM also has a mutase and a phosphatase function, but these are much less active, in contrast to its glycolitic cousin, phosphoglycerate mutase (PGM), which favors these two functions, but can also catalyze the synthesis of 2,3-BPG to a lesser extent.

Because the main function of bisphosphoglycerate mutase is the synthesis of 2,3-BPG, this enzyme is found only in erythrocytes and placental cells. In glycolysis, converting 1,3-BPG to 2,3-BPG would be very inefficient, as it just adds another unnecessary step.