Enzymic preparation and characterization of an α-l-β-methylaspartic acid

Barker, H. A.; Smyth, Robert D.; Wawszkiewicz, E. J.; Lee, Mary N.; Wilson, Rebecca M.

doi:10.1016/0003-9861(58)90371-0

Cited by 69 publications

(17 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fact that anaerobes produce only 1 mol of C 0 2 per mol of glutamate degraded, whereas aerobes theoretically produce 3 mols of COz using the tricarboxylic acid cycle, suggests that a different pathway is used for the metabolism of glutamic acid. Several studies have been done to determine the possible pathways of glutamate catabolism in anaerobic bacteria (see, e.g., Buckel & Barker, 1974). Both Clostridiurn tetanomorphurn and Peptostreptococcus aerogenes were studied extensively, and although both decarboxylate glutamate at position C-5 and produce acetate and butyrate, different metabolic intermediates were recovered (Buckel & Barker, 1974;Lerud & Whitely, 1971;Whitely, 1957).…”

Section: Discussionmentioning

confidence: 99%

“…Several studies have been done to determine the possible pathways of glutamate catabolism in anaerobic bacteria (see, e.g., Buckel & Barker, 1974). Both Clostridiurn tetanomorphurn and Peptostreptococcus aerogenes were studied extensively, and although both decarboxylate glutamate at position C-5 and produce acetate and butyrate, different metabolic intermediates were recovered (Buckel & Barker, 1974;Lerud & Whitely, 1971;Whitely, 1957). In the present study, F. nucleaturn decarboxylated glutamate at C-5, possessed enzymes of the 2-oxoglutarate pathway (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Several studies have been done to determine the role and distribution of this pathway among glutamate-fermenting anaerobes (Buckel & Barker, 1974;Lerud & Whitely, 1971;Horler et al, 1966). Acidoaminococcus fermentans, Micrococcus aerogenes and Peptostreptococcus aerogenes degrade glutamate solely via this pathway, in which the successive intermediates are 2-oxoglutarate, 2-hydroxyglutarate and probably vinylacetyl-CoA and crotonyl-CoA (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Although several studies were undertaken to purify the intermediates of this pathway, the enzyme responsible for the conversion of 2-hydroxyglutarate to crotonyl-CoA via vinylacetyl-CoA still requires investigation. Studies by Buckle & Barker (1974) suggested a role for a dehydratase which required the presence of coenzyme-A and acetyl phosphate. In addition pre-incubation with NADH, FeSO,, MgC12 and dithiothreitol under anaerobic conditions was necessary to attain maximum activity.…”

Section: Discussionmentioning

confidence: 99%

“…The pH optimum for the reaction was determined, then the Michaelis constant was estimated using the following reaction mixture: 0.05 mM-Tris/HCI buffer, pH 7, 500 pl; 150 mM-KCl, 60 pl; 15 mM-MgCl,, 60 1.11; and 100 pl of cell extract. The reaction was initiated by the addition of sodium-L-threo-P-methylaspartate at a concentration ranging from 0.1 x 24 x 10-J M. One unit of enzyme activity was defined as the amount of enzyme required to catalyse an increase in A?,,, of 0.04min-', equivalent to 1.039 x lo-' pmol mesaconate min-' (Barker et al, 1958).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Pathways of glutamate catabolism among Fusobacterium species

Gharbia

Shah

1991

Journal of General Microbiology

View full text Add to dashboard Cite

Glutamate is a major source of energy for Fusobacterium species but its mode of catabolism has not hitherto been elucidated. Cell suspensions of F. nucleaturn and F. varium, as representative species from the oral cavity and gastrointestinal tract, respectively, both decarboxylated position-labelled glutamate but by different pathways.4C02 was released only from C-5 by F. nucleaturn whereas F. varium decarboxylated glutamate at either C-1 or C-5. In both species, 2 mols of glutamate fermented yielded 2 mols of acetate and 1 mol of butyrate, suggesting the possibility of three metabolic pathways: the 2-oxoglutarate, mesaconate and 4-aminobutyrate pathways. Enzymes representative of the three pathways were assayed for in cell-free extracts of fusobacteria. All species tested possessed high levels of both glutamate dehydrogenase and 2-oxoglutarate reductase, indicating the presence of the 2-oxoglutarate pathway. Enzymes representative of the mesaconate pathway were detected in F. sulci, F. ulcerens, F. mortiferum and F. varium, while the latter two species also possessed the 4-aminobutyrate pathway. The pathways of glutamate catabolism therefore bore no relationship to the site of isolation of the fusobacteria tested but instead correlated with their chemotaxonomic properties. Thus, F. verium, F. mortiferum, F. ulcerans and F. sulci, which possess a peptidoglycan structure based on diaminophelic acid, have either two or three pathways for glutamate catabolism whereas F. nucleaturn and other species that have a lanthionine-based murein metabolized glutamate solely by the 2-oxoglutarate pathway.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Pathways of glutamate catabolism among Fusobacterium species

Gharbia

Shah

1991

Journal of General Microbiology

View full text Add to dashboard Cite

show abstract

Enantiospecific enzymatic preparation of (2S,3S)-3-alkylaspartic acids of current interest in the synthesis of stereoregular poly[?-(2S,3S)-3-alkylmalic acids] as new optically active functional polyesters

et al. 1996

View full text Add to dashboard Cite

(2S,3S)‐3‐methyl‐ and 3‐isopropylaspartic acids were synthesized by bioconversion of the corresponding alkylfumarates (mesaconate and 3‐isopropylfumarate) using β‐methylaspartase from cell‐free extracts of Clostridium tetanomorphum. Optically pure (2S,3S)‐3‐alkylaspartic acids were transformed in several steps to benzyl (3S,4R)‐3‐alkylmalolactonates without any racemization of the two chiral centers. These optically active α,β‐substituted‐β‐lactones were polymerized by anionic ring opening polymerization yielding optically active semi‐crystalline polyesters. 13C NMR analysis of poly[benzyl β‐3‐isopropylmalate] in CDCl3 has shown that only the iso‐type stereosequence is present in the polymer, indicating that the macromolecular chain is constituted by the only units of benzyl β‐(2S,3S)‐3‐isopropylmalate monomer. The polymerization reaction was done without any racemization of the two stereogenic centers as in the case of benzyl (3S,4R)‐3‐methylmalolactonate. © 1996 Wiley‐Liss, Inc.

show abstract

Synthesis and polymerization of benzyl (3R,4R)-3-methylmalolactonate via enzymatic preparation of the chiral precursor

Bear¹,

Monne

Robic

et al. 1998

Chirality

View full text Add to dashboard Cite

β‐methylaspartate ammonia‐lyase, EC 4.3.1.2, (β‐methylaspartase) from Clostridium tetanomorphum was used to produce a 40/60 molar ratio of (2S,3R) and (2S,3S)‐3‐methylaspartic acids, 2a and 2b, respectively, from mesaconic acid 1 as substrate, on a large scale. To prepare (3R,4R)‐3‐methyl‐4‐(benzyloxycarbonyl)‐2‐oxetanone (benzyl 3‐methylmalolactonate) 6, 2a and 2b were transformed, in the first step, into 2‐bromo‐3‐methylsuccinic acids 3a and 3b and separated. After three further steps, (2S,3S)‐3a yielded the α,β‐substituted β‐lactone (3R,4R) 6 with a very high diastereoisomeric excess (>95% by chiral gas chromatography). The corresponding crystalline polymer, poly[benzyl β‐(2R,3S)‐3‐methylmalate] 8, prepared by an anionic ring opening polymerization, was highly isotactic as determined by 13C NMR. Catalytic hydrogenolysis of lactone 6 yielded (3R,4R)‐3‐methyl‐4‐carboxy‐2‐oxetanone (3‐methylmalolactonic acid) 7, to which reactive, chiral, or bioactive molecules can be attached through ester bonds leading to polymers with possible therapeutic applications. Because of the ability of β‐methylaspartase to catalyse both syn‐ and anti‐elimination of ammonia from (2S,3RS)‐3‐methylaspartic acid 2ab at different rates, the (2S,3R)‐stereoisomer 2a was retained and isolated for further reactions. These results permit the use of the chemoenzymatic route for the preparation of both optically active and racemic polymers of 3‐methylmalic acid with well‐defined enantiomeric and diastereoisomeric compositions. Chirality 10:727–733, 1998. © 1998 Wiley‐Liss, Inc.

show abstract

Enzymic preparation and characterization of an α-l-β-methylaspartic acid

Cited by 69 publications

References 13 publications

Pathways of glutamate catabolism among Fusobacterium species

Pathways of glutamate catabolism among Fusobacterium species

Enantiospecific enzymatic preparation of (2S,3S)-3-alkylaspartic acids of current interest in the synthesis of stereoregular poly[?-(2S,3S)-3-alkylmalic acids] as new optically active functional polyesters

Synthesis and polymerization of benzyl (3R,4R)-3-methylmalolactonate via enzymatic preparation of the chiral precursor

Contact Info

Product

Resources

About