Folate distribution in cultured human cells. Studies on 5,10-CH2-H4PteGlu reductase deficiency.

We have studied the distribution of folate coenzyme forms in cultured human fibroblasts from control lines and from lines derived from nine patients representing all of the published reports of 5,10-CH(2)-H(4)PteGlu reductase deficiency. Based on mobility on DEAE-Sephadex and differential microbiological assay the major folate fractions in extracts of human fibroblasts were 5-CH(3)-H(4)PteGlu, 10-CHO-H(4)PteGlu, and 5-CHO-H(4)PteGlu with smaller fractions, which included 5-CH(3)-H(2)PteGlu, 10-CHO-PteGlu, and H(4)PteGlu. Evidence that the 5-CHO-H(4)PteGlu may have been derived from 5,10-CH=H(4)PteGlu during extraction is presented.