The interconversion of serine and glycine: some further properties of the enzyme system

The partial purification from rabbit liver of a soluble enzyme system which catalyses the net synthesis of serine from glycine and formaldehyde has been previously reported (Blakley, 1955), together with evidence for the participation of pyridoxal phos- phate. Further work has had as its chief aim elucidation of the role of tetrahydropteroylglutamic acid (tetrahydroPGA) in this enzymic reaction, but in the course of these investigations certain pro- perties of the enzyme system have been deter- mined. It is the purpose of this paper to present these results, the most important of which concern the specificity of the enzyme system for tetrahydro- PGA as the coenzyme.