Localization and interconversion of tetrahydropteroylglutamates in isolated pea mitochondria.
1. Mitochondria were extracted from 4-day-old pea cotyledons and purified on a sucrose density gradient. 2. Microbiological assay of the purified mitochondrial fraction with Lactobacillus casei (A.T.C.C. 7469), Streptococcus faecalis (A.T.C.C. 8043) and Pediococcus cerevisiae (A.T.C.C. 8081) revealed a discrete pool of conjugated and unconjugated derivatives of tetrahydropteroylglutamic acid. 3. Solubilization and chromatographic studies of the mitochondrial fraction demonstrated the presence of formylated and methylated derivatives, 10-formyltetrahydropteroylmonoglutamic acid, 5-formyltetrahydropteroylmonoglutamic acid and 5-formyltetrahydropteroyldiglutamic acid being the major derivatives present. 4. The principal mitochondrial pteroylglutamates were labelled when dry seeds were allowed to imbibe [2-(14)C]pteroylglutamic acid and 5-[methyl-(14)C]-methyltetrahydropteroylmonoglutamic acid. 5. The ability of isolated mitochondria to catalyse oxidation and reduction of tetrahydropteroylglutamic acid derivatives was demonstrated in feeding experiments in which [(14)C]formaldehyde, [3-(14)C]serine, sodium [(14)C]formate, 5-[methyl-(14)C]methyltetrahydropteroylmonoglutamic acid or [2-(14)C]-glycine served as C(1) donor. In addition, (14)C was incorporated into free amino acids related to C(1) metabolism.
D002247:Carbon Isotopes; D002499:Centrifugation, Density Gradient; D002848:Chromatography, DEAE-Cellulose; D003067:Coenzymes / Q000032:analysis*; D013293:Enterococcus faecalis; D005492:Folic Acid / Q000032:analysis* / Q000378:metabolism; D007780:Lacticaseibacillus casei; D008826:Microbial Sensitivity Tests; D008928:Mitochondria / Q000032:analysis*; D010376:Pediococcus; D010944:Plants / Q000378:metabolism*; D013395:Sucrose; D013763:Tetrahydrofolates / Q000032:analysis / Q000378:metabolism
D002247:Carbon Isotopes; D003067:Coenzymes; D013763:Tetrahydrofolates; D013395:Sucrose; D005492:Folic Acid