Search results
Results from the WOW.Com Content Network
Porphobilinogen (PBG) is an organic compound that occurs in living organisms as an intermediate in the biosynthesis of porphyrins, which include critical substances like hemoglobin and chlorophyll. [ 1 ]
It catalyzes the following reaction, the second step of the biosynthesis of porphyrin: 2 5-Aminolevulinic acid porphobilinogen + 2 H 2 O. It therefore catalyzes the condensation of 2 molecules of 5-aminolevulinate to form porphobilinogen (a precursor of heme, cytochromes and other hemoproteins). This reaction is the first common step in the ...
The dominance pattern is a result of partial deficiencies from the heme biosynthesis enzymes, hydroxymethylbilane synthase (HMBS; EC 2.5.1.61). [25] Due to the rarity of this disease it is difficult to estimate the prevalence of AIP and the inclusion criteria differs widely among studies causing varying statistics.
The biosynthesis of pyrrole rings begins with aminolevulinic acid (ALA), which is synthesized from glycine and succinyl-CoA. ALA dehydratase catalyzes the condensation of two ALA molecules via a Knorr-type ring synthesis to form porphobilinogen (PBG). This later reacts to form, for example, the macrocycles heme and chlorophyll. [26]
The most well-known health issue involving porphobilinogen deaminase is acute intermittent porphyria, an autosomal dominant genetic disorder where insufficient hydroxymethylbilane is produced, leading to a build-up of porphobilinogen in the cytoplasm. This is caused by a gene mutation that, in 90% of cases, causes decreased amounts of enzyme.
Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme-catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthesis) serve as enzyme substrates, with conversion by the living organism either into simpler or more complex ...
δ-Aminolevulinic acid (also dALA, δ-ALA, 5ALA or 5-aminolevulinic acid), an endogenous non-proteinogenic amino acid, is the first compound in the porphyrin synthesis pathway, the pathway that leads to heme [3] in mammals, as well as chlorophyll [4] in plants.
Aminolevulinic acid synthase (ALA synthase, ALAS, or delta-aminolevulinic acid synthase) is an enzyme (EC 2.3.1.37) that catalyzes the synthesis of δ-aminolevulinic acid (ALA) the first common precursor in the biosynthesis of all tetrapyrroles such as hemes, cobalamins and chlorophylls. [1] The reaction is as follows: