Studies on the biosynthesis of blood pigments. 4. The nature of the porphyrins formed on incubation of chicken erythrocyte preparations with glycine, δ-aminolaevulic acid or porphobilinogen

The oxygen-independent coproporphyrinogen III oxidase HemN utilizes harderoporphyrinogen as a reaction intermediate during conversion of coproporphyrinogen III to protoporphyrinogen IX

“…The two additional peaks probably correspond to by-products of hydrolysis and sodium amalgam reduction, at retention times of 9 and 6.5 min. These contaminants were not further investigated; however, it has been reported that by-products are formed during hydrolysis of porphyrins containing a vinyl group in HCl solution and during sodium amalgam reduction (Falk et al, 1956). Therefore, the substrate solution used for the HemN activity assays consisted of a mixture of harderoporphyrinogen and two porphyrinogens that were not further characterized (Figure 4).…”

Investigations of the Role of Iron in Chlorophyll Metabolism I. Effect of Iron Deficiency on Chlorophyll and Heme Content and on the Activities of Certain Enzymes in Leaves

“…It was reported (15) that the activities of the enzymic systems involved in the synthesis of protoporphyrin from baminolevulinic acid (b-AL) were not reduced by iron deficiency, yet protoporphyrin failed to accumulate in iron-deficient leaves unless the tissue was incubated in the dark with b-AL. Since protoporphyrin is a precursor of both chlorophyll and heme (12) (14) and in avian blood (5, 6, 17) lhas been suggested. The reaction mediated by aconitase may limit the rate of b-AL synthesis in iron-deficient tissues of animals (9,16) and plants (3).…”

Synthesis of porphyrins by cell suspensions of Tetrahymena vorax: effect of members of the vitamin B group

“…Protoporphyrin was also formned (20-30 % of the total) together with coproporphyrin III (15-25 % of the total). These three porphyrins are also formed predominantly by chick-erythrocyte preparations when incubated with ALA or with porphobilinogen (Falk et al 1956).…”

“…Effect of Members of the Vitamin B Group BY JUNE LASCELLES* Microbiology Unit, Department of Biochemi8try, Univer8ity of Oxford (Received 13 September 1956) It is well established that the biosynthesis of the porphyrin nucleus in animal tissues proceeds by condensation of glycine with an unsymmetrical derivative of succinate (derived from the tricarboxylic acid cycle) with intermediate formation of 8-aminolaevulic acid (ALA) and porphobilinogen (Shemin, 1955; Dresel & Falk, 1956a-c;Falk, Dresel, Benson & Knight, 1956;Berlin, Neuberger & Scott, 1956a, b). There is evidence that a similar pathway occurs in photosynthetic bacteria of the Athiorhodaceae group (Lascelles, 1955;Cooper, 1956…”