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Glycine protoporphyrin

Fig. 2. Pathway of the synthesis of heme and chlorophyll, (a) Synthesis of porphobilinogen from glycine and succlnyl CoA (b) synthesis of protoporphyrin IX from porphobilinogen. A = CH2COOH, M = CH3, P = CH2CH2COOH. Fig. 2. Pathway of the synthesis of heme and chlorophyll, (a) Synthesis of porphobilinogen from glycine and succlnyl CoA (b) synthesis of protoporphyrin IX from porphobilinogen. A = CH2COOH, M = CH3, P = CH2CH2COOH.
A third group of OMTs are the protein carboxyl MTs, whose molecular mass is approximately 27 kDa 43 These proteins are found in almost all organisms, and they serve to repair damaged proteins. In plants, they have been shown to be important during stress and in seed viability.14. Their sequences are related to the animal glycine N-methyltransferases (NMTs) and die RNA/DNA MTs. Furthermore, the plant protein carboxyl MTs share no similarity to the other plant MTs involved in specialized metabolism. The enzyme that methylates a carboxyl functionality of Mg-protoporphyrin IX to produce a methylester constitutes a fourth type of plant OMT. This chloroplastic protein, whose mature form has a molecular mass of 31 kDa, is related to MTs with similar functions from photosynthetic bacteria, but is not closely related to any other plant OMTs.6... [Pg.257]

Heme is an iron- and nitrogen-containing porphyrin ring system synthesized from glycine and succinyl-CoA. Protoporphyrin IX, the precursor of heme, is also a precursor of the chlorophylls. [Pg.499]

The same ring systems but with different substituents arise from different sources, the pyrrol ring in protoporphyrins having its ultimate origin in glycine and succinic acid (385). [Pg.18]

Figure 10.4 Putative pre-biotic chemistry route of conversion of cyano-aspartic and cyano-glycine (a-amino nitriles) into cyano-uroporphyrinogen III, the anaerobic equivalent to the key biosynthetic intermediate uroporphyrinogen III that is required for the subsequent formation of cofactor protoporphyrin IX found in myoglobin, hemoglobin and cytochrome c (see Chapter 1). Uroporphyrinogen III also gives rise to many other porphryin-related pigments employed in respiration and photosynthesis. Figure 10.4 Putative pre-biotic chemistry route of conversion of cyano-aspartic and cyano-glycine (a-amino nitriles) into cyano-uroporphyrinogen III, the anaerobic equivalent to the key biosynthetic intermediate uroporphyrinogen III that is required for the subsequent formation of cofactor protoporphyrin IX found in myoglobin, hemoglobin and cytochrome c (see Chapter 1). Uroporphyrinogen III also gives rise to many other porphryin-related pigments employed in respiration and photosynthesis.
It was first demonstrated in 1945 that glycine was utilized for the synthesis of protoporphyrin in man [367], and it was possible with [ N]glycine to show... [Pg.64]

Subsequently it was shown using [ N]glycine that all 4 nitrogen atoms in protoporphyrin were derived from that amino acid [372]. It is now known that one molecule of glycine and one molecule of succinyl-CoA condense to form one molecule of a-aminolaevulinic acid (ALA). Two molecules of ALA are then linked by the action of cytoplasmic ALA dehydrase to form porphobilinogen (PBG). Four molecules of PBG form a tetrapyrrole, uroporphyrinogen, and subsequently by decarboxylation and oxidation of the side chains, protoporphyrin IX is formed which combines with iron to form haem. Use has been made of both and precursors to elucidate the intermediate steps involved in haem synthesis [373—378]. Much of the early work covering the biosynthesis of porphyrin has been reviewed in detail [379]. [Pg.65]

The biosynthetic chain of chlorophyll begins with the small building blocks, acetate and glycine molecules, which are part of the basic metabolic milieu. These small molecules are condensed in a series of n steps to form the complex molecule protoporphyrin. From protoporphyrin two classes of compounds are formed namely, the iron porphyrins or hemes and the magnesium porphyrins which give rise eventually to chlorophyll. According to this scheme, heme and chlorophyll are related to each other biochemically, since both arise from the same precursor molecule, protoporphyrin. [Pg.291]

Knowledge of the building blocks of protoporphyrin (more specifically of iron protoporphyrin) is derived primarily from recent tracer studies (see below). The results of the tracer studies indicate that the porphyrin molecule is built up of eight glycine and eight 4-carbon units. The specific 4-carbon unit is as yet unidentified it appears to be an intermediate of the citric-acid cycle (or derived from an intermediate)— possibly an intermediate between a-ketoglutarate and succinic acid. [Pg.295]

Fig. 13. Degradation studies to demonstrate equal utilization of glycine-N in the two types of pyrrole rings of protoporphyrin. (Double bonds of the porphyrins are omitted. Fig. 13. Degradation studies to demonstrate equal utilization of glycine-N in the two types of pyrrole rings of protoporphyrin. (Double bonds of the porphyrins are omitted.
Only the -Carbon Atoms op Glycine and Not the Carboxyl-Carbon Atoms Are Contained in Protoporphyrin... [Pg.315]

Glycine can follow any one of a number of paths and during metabolism it may be transformed into a variety of substances formate, acetate, ethanolamine, serine, aspartic acid, fatty adds, purines, pyrimidines, ribose or protoporphyrin. Its complete degradation, like that of serine or ethanolamine into which it is readily transformed, may be brought about by conversion to pyruvic acid from whence it can enter the glycolysis chain or the tricarboxylic acid cycle. [Pg.221]

Synthesis of haem is readily accomplished from simple precursors. In the first step of porphyrin synthesis succinyl-CoA, which is produced in the citrate cycle and during the metabolism of various amino acids, is condensed with glycine to give d-aminolaevulinic acid, and it is this reaction which is rate-controlling. Subsequently two molecules of d-aminolaevulinic acid condense to form porphobilinogen and four molecules of porphobilinogen undergo a series of reactions to produce protoporphyrin which combines with ferrous ions to form haem. [Pg.372]


See other pages where Glycine protoporphyrin is mentioned: [Pg.197]    [Pg.18]    [Pg.14]    [Pg.173]    [Pg.229]    [Pg.1023]    [Pg.603]    [Pg.753]    [Pg.753]    [Pg.401]    [Pg.410]    [Pg.60]    [Pg.732]    [Pg.518]    [Pg.293]    [Pg.3]    [Pg.188]    [Pg.128]    [Pg.23]    [Pg.65]    [Pg.109]    [Pg.161]    [Pg.287]    [Pg.305]    [Pg.305]    [Pg.311]    [Pg.313]    [Pg.315]    [Pg.315]    [Pg.318]    [Pg.404]    [Pg.65]   
See also in sourсe #XX -- [ Pg.535 ]




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Protoporphyrin

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