Engineered ACVS and IPNS for Fermentative Beta-Lactam Production
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Solution Overview
Problem
Current methods for producing β-lactam antibiotics, such as penicillins and cephalosporins, rely on semi-synthetic routes that are costly, environmentally unfriendly, and involve multiple steps, limiting the direct fermentative production of antibiotics like amoxicillin and cefalexin due to enzyme specificity constraints.
Innovation Solution
Engineering the δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine synthetase (ACVS) and Isopenicillin N synthase (IPNS) enzymes to catalyze the formation of non-native tripeptides like HpgCV and PgCV, allowing for the fermentative production of β-lactam antibiotics by modifying the substrate specificity and stereochemistry, enabling the conversion of these tripeptides into antibiotics like amoxicillin and ampicillin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If semi-synthetic methods are used to produce β-lactam antibiotics, then the production of antibiotics with specific side chains (e.g., amoxicillin, cefalexin) is achieved, but the process becomes costly, environmentally unfriendly, and involves multiple steps
Solution Approach 1:
The patent changes the substrate specificity parameter of the ACVS enzyme through genetic engineering, allowing it to accept alternative amino acid substrates (phenylglycine, hydroxyphenylglycine) in addition to the native α-aminoadipic acid. This parameter change enables the enzyme to produce the desired tripeptide precursors for amoxicillin and cefalexin directly in fermentation, eliminating the need for semi-synthetic conversion steps while maintaining high production efficiency
Solution Approach 2:
The engineered ACVS enzyme acquires multiple substrate specificities, functioning as a universal synthetase that can process different amino acid substrates (α-aminoadipic acid, phenylglycine, hydroxyphenylglycine) to produce various tripeptide intermediates. This multi-functionality allows a single fermentation process to produce multiple different β-lactam antibiotics by simply changing the amino acid feed, eliminating the need for separate semi-synthetic production lines
2Reliability
If enzyme substrate specificity is maintained (native ACVS and IPNS), then the biosynthetic pathway produces standard penicillins, but the production of antibiotics like amoxicillin and cefalexin cannot be achieved directly through fermentation
Solution Approach 1:
The patent modifies the substrate specificity parameter of the ACVS enzyme through site-directed mutagenesis and selection, enabling it to recognize and process alternative amino acid substrates. The enzyme retains its core catalytic function (reliability) while gaining the ability to incorporate phenylglycine and hydroxyphenylglycine into the tripeptide structure, thereby achieving the adaptability needed to produce amoxicillin and cefalexin precursors directly in fermentation
Solution Approach 2:
The patent creates a dynamic enzyme system where the ACVS substrate specificity can be adjusted by changing the amino acid composition in the fermentation medium. The engineered enzyme exhibits flexible substrate recognition, allowing the same biosynthetic pathway to produce different tripeptide intermediates depending on which amino acids are provided, thus adapting to produce various final antibiotic products
3Manufacturing precision
If the tripeptide ACV is oxidatively cyclised by IPNS, then Isopenicillin N is formed with the typical β-lactam and thiazolidine ring structures, but the side chain exchange for industrially important penicillins cannot be performed directly
Solution Approach 1:
The patent performs preliminary action by engineering the ACVS enzyme to incorporate the desired side chain amino acids (phenylglycine, hydroxyphenylglycine) directly into the tripeptide structure during synthesis. This preliminary incorporation of the correct side chain precursors eliminates the need for subsequent side chain exchange reactions, simplifying the overall process while maintaining the precision of β-lactam ring formation by IPNS
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables a completely fermentative production of β-lactam antibiotics, reducing costs and environmental impact by bypassing semi-synthetic methods and improving enzyme specificity, thereby enhancing the efficiency and sustainability of antibiotic production.
Implementation Method 1
contacting a tripeptide hydroxyphenylglycyl-cysteinyl-valine (HpgCV) or a tripeptide phenylglycyl-cysteinyl-valine (PgCV) with an IPNS to effect formation of the N-α-amino-hydroxyphenylacetyl or the N-α-aminophenylacetyl β-lactam antibiotic
Implementation Method 2
the tripeptide ACV is oxidatively cyclised by the action of Isopenicillin N synthase (hereinafter referred to as IPNS) or cyclase
Implementation Method 3
This step is catalyzed by δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine synthetase or ACVS
Implementation Method 4
the condensation of the L-isomers of three amino acids, L-α-amino adipic acid (A), L-cystein (C) and L-valine (V) into a tripeptide
Data Source
AI summary
The present invention describes a process for the production of an N-α-amino-hydroxyphenylacetyl or an N-α-aminophenylacetyl β-lactam antibiotic comprising an IPNS-catalysed conversion of a precursor tripeptide hydroxyphenylglycyl-cysteinyl-valine (HpgCV) or phenylglycyl-cysteinyl-valine (PgCV), respectively, to the N-hydroxyphenylglycyl or the N-phenylglycyl β-lactam antibiotic, respectively. The tripeptide HpgCV or the tripeptide PgCV may further be prepared by contacting the amino acids hydroxyphenylglycine (Hpg) or phenylglycine (Pg), cystein (C) and valine (V) with a non-ribosomal peptide synthetase (NRPS) to effect formation of the tripeptide HpgCV or the tripeptide PgCV, the NRPS comprising a first module M1 specific for Hpg or Pg, a second module M2 specific for C and a third module M3 specific for V An IPNS is further provided having an improved activity in this conversion, as well as an NRPS catalysing the formation of the tripeptides. Also a host cell is provided capable of fermentatively producing β-lactam antibiotics with N-α-amino-hydroxyphenylacetyl or an N-α-aminophenylacetyl side chains.