Folic acid cleaving enzyme

This activity (FAS) cleaves folic acid into pterin-6-aldehyde and p-aminobenzoylglutamic acid, and the HPLC assay developed for it involves the separation of the two. 

The separation was carried out on a reversed phase HPLC column (Li-Chrosorb 10 RP-18) or on an anion exchanger (Partisil PXS 10/25 SAX). For pterin-6-aldehyde, the mobile phase was a 15 mM phosphate buffer (pH 6.0) with 10% methanol. For p-aminobenzoylglutamic acid, a 0.1M NH3 solution containing 0.2M NaCl, 20% (v/v) 1-propanol, and 10% (v/v) acetonitrile adjusted to pH 5.32 with acetic acid was used. Both columns were eluted isocrati-cally, and the detection was by UV at 254 nm and by liquid scintillation counting. 

The enzyme activity was from the cellular slime mold Dictyostelium mi-nutum. 

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