19883-78-4Relevant articles and documents
A novel phenylalanine ammonia-lyase from Pseudozyma antarctica for stereoselective biotransformations of unnatural amino acids
Varga, Andrea,Csuka, Pál,Sonesouphap, Orlavanah,Bánóczi, Gergely,To?a, Monica Ioana,Katona, Gabriel,Molnár, Zsófia,Bencze, László Csaba,Poppe, László,Paizs, Csaba
, p. 185 - 194 (2020/04/28)
A novel phenylalanine ammonia-lyase of the psychrophilic yeast Pseudozyma antarctica (PzaPAL) was identified by screening microbial genomes against known PAL sequences. PzaPAL has a significantly different substrate binding pocket with an extended loop (26 aa long) connected to the aromatic ring binding region of the active site as compared to the known PALs from eukaryotes. The general properties of recombinant PzaPAL expressed in E. coli were characterized including kinetic features of this novel PAL with L-phenylalanine (S)-1a and further racemic substituted phenylalanines rac-1b-g,k. In most cases, PzaPAL revealed significantly higher turnover numbers than the PAL from Petroselinum crispum (PcPAL). Finally, the biocatalytic performance of PzaPAL and PcPAL was compared in the kinetic resolutions of racemic phenylalanine derivatives (rac-1a-s) by enzymatic ammonia elimination and also in the enantiotope selective ammonia addition reactions to cinnamic acid derivatives (2a-s). The enantiotope selectivity of PzaPAL with o-, m-, p-fluoro-, o-, p-chloro- and o-, m-bromo-substituted cinnamic acids proved to be higher than that of PcPAL.
Kinetic Resolution of Aromatic β-Amino Acids Using a Combination of Phenylalanine Ammonia Lyase and Aminomutase Biocatalysts
Weise, Nicholas J.,Ahmed, Syed T.,Parmeggiani, Fabio,Turner, Nicholas J.
, p. 1570 - 1576 (2017/05/05)
An enzymatic strategy for the preparation of (R)-β-arylalanines employing phenylalanine aminomutase and ammonia lyase (PAM and PAL) enzymes has been demonstrated. Candidate PAMs with the desired (S)-selectivity from Streptomyces maritimus (EncP) and Bacillus sp. (PabH) were identified via sequence analysis using a well-studied template sequence. The newly discovered PabH could be linked to the first ever proposed biosynthesis of pyloricidin-like secondary metabolites and was shown to display better β-lyase activity in many cases. In spite of this, a method combining the higher conversion of EncP with a strict α-lyase from Anabaena variabilis (AvPAL) was found to be more amenable, allowing kinetic resolution of five racemic substrates and a preparative-scale reaction with >98% (R) enantiomeric excess. This work represents an improved and enantiocomplementary method to existing biocatalytic strategies, allowing simple product separation and modular telescopic combination with a preceding chemical step using an achiral aldehyde as starting material. (Figure presented.).
Influence of the aromatic moiety in α- And β-arylalanines on their biotransformation with phenylalanine 2,3-aminomutase from: Pantoea agglomerans
Varga, Andrea,Bánóczi, Gergely,Nagy, Botond,Bencze, László Csaba,To?a, Monica Ioana,Gellért, ákos,Irimie, Florin Dan,Rétey, János,Poppe, László,Paizs, Csaba
, p. 56412 - 56420 (2016/07/06)
In this study enantiomer selective isomerization of various racemic α- and β-arylalanines catalysed by phenylalanine 2,3-aminomutase from Pantoea agglomerans (PaPAM) was investigated. Both α- and β-arylalanines were accepted as substrates when the aryl moiety was relatively small, like phenyl, 2-, 3-, 4-fluorophenyl or thiophen-2-yl. While 2-substituted α-phenylalanines bearing bulky electron withdrawing substituents did not react, the corresponding substituted β-aryl analogues were converted rapidly. Conversion of 3- and 4-substituted α-arylalanines happened smoothly, while conversion of the corresponding β-arylalanines was poor or non-existent. In the range of pH 7-9 there was no significant influence on the conversion of racemic α- or β-(thiophen-2-yl)alanines, whereas increasing the concentration of ammonia (ammonium carbonate from 50 to 1000 mM) inhibited the isomerization progressively and decreased the amount of the by-product (i.e. (E)-3-(thiophen-2-yl)acrylic acid was detected). In all cases, the high ee values of the products indicated excellent enantiomer selectivity and stereospecificity of the isomerization except for (S)-2-nitro-α-phenylalanine (ee 92%) from the β-isomer. Substituent effects were rationalized by computational modelling revealing that one of the main factors controlling biocatalytic activity was the energy difference between the covalent regioisomeric enzyme-substrate complexes.
Telescopic one-pot condensation-hydroamination strategy for the synthesis of optically pure L-phenylalanines from benzaldehydes
Parmeggiani, Fabio,Ahmed, Syed T.,Weise, Nicholas J.,Turner, Nicholas J.
, p. 7256 - 7262 (2016/10/26)
A chemo-enzymatic telescopic approach was designed for the synthesis of L-arylalanines in high yield and optical purity, starting from commercially available and inexpensive substituted benzaldehydes. The method exploits a chemical Knoevenagel–Doebner condensation (optimised to give complete conversions in a short reaction time, employing microwave irradiation) and a biocatalytic phenylalanine ammonia lyase mediated hydroamination (for the stereoselective addition of ammonia). The two reactions can be run sequentially in one pot, bringing together the advantages of chemical and biological catalysis. The preparative applicability was demonstrated with the synthesis of five L-dihalophenylalanines (71–84% yield, 98–99% ee) of relevance as molecular probes, for medicinal chemistry and for the synthesis of pharmaceutical ingredients.
Intensified biocatalytic production of enantiomerically pure halophenylalanines from acrylic acids using ammonium carbamate as the ammonia source
Weise, Nicholas J.,Ahmed, Syed T.,Parmeggiani, Fabio,Siirola, Elina,Pushpanath, Ahir,Schell, Ursula,Turner, Nicholas J.
, p. 4086 - 4089 (2016/07/06)
An intensified, industrially-relevant strategy for the production of enantiopure halophenylalanines has been developed using the novel combination of a cyanobacterial phenylalanine ammonia lyase (PAL) and ammonium carbamate reaction buffer. The process boasts STYs up to >200 g L-1 d-1, ees ≥ 98% and simplified catalyst/reaction buffer preparation and work up.
The bacterial ammonia lyase EncP: A tunable biocatalyst for the synthesis of unnatural amino acids
Weise, Nicholas J.,Parmeggiani, Fabio,Ahmed, Syed T.,Turner, Nicholas J.
supporting information, p. 12977 - 12983 (2015/10/28)
Enzymes of the class I lyase-like family catalyze the asymmetric addition of ammonia to arylacrylates, yielding high value amino acids as products. Recent examples include the use of phenylalanine ammonia lyases (PALs), either alone or as a gateway to deracemization cascades (giving (S)- or (R)-α-phenylalanine derivatives, respectively), and also eukaryotic phenylalanine aminomutases (PAMs) for the synthesis of the (R)-β-products. Herein, we present the investigation of another family member, EncP from Streptomyces maritimus, thereby expanding the biocatalytic toolbox and enabling the production of the missing (S)-β-isomer. EncP was found to convert a range of arylacrylates to a mixture of (S)-α- and (S)-β-arylalanines, with regioselectivity correlating to the strength of electron-withdrawing/-donating groups on the ring of each substrate. The low regioselectivity of the wild-type enzyme was addressed via structure-based rational design to generate three variants with altered preference for either α- or β-products. By examining various biocatalyst/substrate combinations, it was demonstrated that the amination pattern of the reaction could be tuned to achieve selectivities between 99:1 and 1:99 for β:α-product ratios as desired.
Synthesis of D- and L-Phenylalanine Derivatives by Phenylalanine Ammonia Lyases: A Multienzymatic Cascade Process
Parmeggiani, Fabio,Lovelock, Sarah L.,Weise, Nicholas J.,Ahmed, Syed T.,Turner, Nicholas J.
, p. 4608 - 4611 (2015/04/14)
The synthesis of substituted D-phenylalanines in high yield and excellent optical purity, starting from inexpensive cinnamic acids, has been achieved with a novel one-pot approach by coupling phenylalanine ammonia lyase (PAL) amination with a chemoenzymatic deracemization (based on stereoselective oxidation and nonselective reduction). A simple high-throughput solid-phase screening method has also been developed to identify PALs with higher rates of formation of non-natural D-phenylalanines. The best variants were exploited in the chemoenzymatic cascade, thus increasing the yield and ee value of the D-configured product. Furthermore, the system was extended to the preparation of those L-phenylalanines which are obtained with a low ee value using PAL amination.
Asymmetric synthesis of unnatural amino acids and tamsulosin chiral intermediate
Arava, Veera Reddy,Amasa, Srinivasulu Reddy,Goud Bhatthula, Bharat Kumar,Kompella, Laxmi Srinivas,Matta, Venkata Prasad,Subha
supporting information, p. 2892 - 2897 (2013/09/02)
An efficient and enantioselective hydrogenation of N-acetylamino phenyl acrylic acids was successfully developed by using ruthenium catalyst. This methodology is important in the field of pharmaceuticals and provides a new process for the preparation of unnatural amino acids and tamsulosin chiral intermediate.
Enzymatic synthesis of chiral phenylalanine derivatives by a dynamic kinetic resolution of corresponding amide and nitrile substrates with a multi-enzyme system
Yasukawa, Kazuyuki,Asano, Yasuhisa
, p. 3327 - 3332 (2013/01/15)
Mutant α-amino-ε-caprolactam (ACL) racemase (L19V/L78T) from Achromobacter obae with improved substrate specificity toward phenylalaninamide was obtained by directed evolution. The mutant ACL racemase and thermostable mutant D-amino acid amidase (DaaA) from Ochrobactrum anthropi SV3 co-expressed in Escherichia coli (pACLmut/pDBFB40) were utilized for synthesis of (R)-phenylalanine and non-natural (R)-phenylalanine derivatives (4-OH, 4-F, 3-F, and 2-F-Phe) by dynamic kinetic resolution (DKR). Recombinant E. coli with DaaA and mutant ACL racemase genes catalyzed the synthesis of (R)-phenylalanine with 84% yield and 99% ee from (RS)-phenylalaninamide (400 mM) in 22 h. (R)-Tyrosine and 4-fluoro-(R)-phenylalanine were also efficiently synthesized from the corresponding amide compounds. We also co-expresed two genes encoding mutant ACL racemase and L-amino acid amidase from Brevundimonas diminuta in E. coli and performed the efficient production of various (S)-phenylalanine derivatives. Moreover, 2-aminophenylpropionitrile was converted to (R)-phenylalanine by DKR using a combination of the non-stereoselective nitrile hydratase from recombinamt E. coli and mutant ACL racemase and DaaA from E. coli encoding mutant ACL racemase and DaaA genes. Copyright
