L-aspartate-p-decarboxylase

A number of decarboxylase enzymes have been described as catalysts for the preparation of chiral synthons, which are difficult to access chemically (see Chapter 2).264 The amino acid decarboxylases catalyze the pyridoxal phosphate (PLP)-dependent removal of C02 from their respective substrates. This reaction has found great industrial utility with one specific enzyme in particular, L-aspartate-P-decarboxylase (E.C. 4.1.1.12) from Pseudomonas dacunhae. This biocatalyst, most often used in immobilized whole cells, has been utilized by Tanabe to synthesize L-alanine on an industrial scale (multi-tons) since the mid-1960s (Scheme 19.33).242-265 Another use for this biocatalyst has been the resolution of racemic aspartic acid to produce L-alanine and D-aspartic acid (Scheme 19.34). The cloning of the L-aspartate-P-decarboxylase from Alcaligenes faecalis into E. coli offers additional potential to produce both of these amino acids.266... 

L-alanine can be prepared from aspartic acid (Figure A8.13). L-Aspartate-P-decarboxylase produced by Xanthomonas oryzae No 531 has been used to prepared L-alanine in 95% yield from 15% L-asp>artic add solution. Other strains, ie Pseudomonas dacunhae or Achromobacter pestifer, give comparable yields of L-alanine. The jntKess has been commerdalised by Tanabe. 

Production of L-alanine by decarboxylation of L-aspartic acid under the action of the intracellular L-aspartate-P-decarboxylase in Pseudomonas dacunhae (Tanabe Seiyaku Co., Ltd). A 1000-liter pressurized column bioreactor can typically yield 5 tons of L-alanine per month. 

Aspartic acid, alanine, phenylalanine, and lysine were manufactured by enzymatic route. Immobilized E. coli cells expressing aspartate or the immobilized enzyme has been used in the commercial production of aspartic acid from ammonia and fumaric acid. Chibata and coworkers also produced alanine by microbial Pseudomonas dacunhae) L-aspartate P-decarboxylase with aspartate as the starting material. Phenyl alanine was manufactured from fw s-cinnamic acid and ammonia by the enzymatic route by phenyl alanine ammonia lyase as catalyst or from phenyl pyruvate and aspartic acid using transaminase. 

P. Strop, H. Gehring, J. N. Jansonius, and P. Christen, Conversion of aspartate aminotransferase into an L-aspartate /3-decarboxylase by a triple active-site mutation, J. Biol. Chem. 1999, 274, 31203-31208. 

The combined utilization in a single reactor of both aspartase from Brevibacterium flavum and aspartate-P-decarboxylase from Pseudomonas dacunhae, thereby catalyzing the reaction from fumaric acid via L-aspartic acid to L-alanine (5), has also been developed by Mitsubishi 5. ... 

L-Alanine (from L-aspartate) L-Aspartate-4-decarboxylase P. decumhae... 

L-Alanine is produced from L-aspartate by a one-step enzymatic method using aspartate P-decarboxylase (Chibata et al. 1986a) (O Fig. 4.2). 

L-aspartate-a-decarboxylase, which leads to the formation of p-alanine, and further nitrogenous products are formed, as shown in Fig. 15.2. 

Konst, P.M., Franssen, M.C.R., Scott, E.L., Sanders, J.P.M., 2009. A study on the applicability of L-aspartate a-decarboxylase in the biobased production of nitrogen containing chemicals. Green Chemistry 11, 1646-1652. 

Also Tanabe have extended the use of that aspartic acid producing process by using the L-aspartic acid as the substrate for L-alanine production using P. dacunae cells with L-aspartate decarboxylase activity. This process has been operating since 1982 using sequential colunms of iimnobihsed E. coli and P. dacunae cells (Chibata, Tosa and Takamatsu, 1987). Also, DL-aspartic acid can be used as the feed in this process. Then, D-aspartic acid is obtained as an additional product, for which there is a modest demand. 

A similar process is also used for the production of L-malic acid from fumarate, in this case using a hydratase enzyme derived from Brevibacterium ammoniagenes. Another variation of the Tanabe technology involves the synthesis of L-alanine from L-aspartic acid through the use of immobilized whole cells (P dacunae) containing aspartate-decarboxylase. 

The decarboxylation of L-aspartic acid to L-alanine is catalysed by a pyridoxal-P-dependent j8-decarboxylase whose reaction mechanism is clearly different from that of the a-decarboxylases since the initial step probably involves C -H bond cleavage. The steric course at during the normal decarboxylation reaction has recently been shown [23b] to be inversion. In addition to this, however, the enzyme will also catalyse the decarboxylation of amino-malonic acid to glycine and Meister and coworkers [24,25] have shown that this process involves loss of the Si carboxyl group with overall retention at C . 

Pantothenic acid is synthesized in plants and some microorganisms from pantoic acid and p-alanine. Pantoic acid is formed from 2-oxopantoic acid (4-hydroxy-3,3-dimethyl-2-oxobutyric acid) and 2-oxoisovaleric acid (3-methyl-2-oxobu-tyric acid), a precursor of valine. P-Alanine is formed by decarboxylation of l-aspartic acid. Enzymes involved include pantothenate synthetase (EC 6.3.2.1), oxopantoate reductase (EC 1.1.1.169), oxopantoate hydroxymethyltransferase (EC 4.1.2.12), and aspartate 1-decarboxylase (EC 4.1.1.12). 

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