A “Second-Generation Process” for the Synthesis of l-Neopentylglycine:  Asymmetric Reductive Amination Using a Recombinant Whole Cell Catalyst

Abstract

A "second-generation process" for the enantioselective synthesis of L-neopentylglycine has been developed, realizing the first whole cell-catalyzed approach to this pharmaceutically interesting, bulky amino acid. The synthesis of this nonnatural amino acid proceeds highly efficiently via a reductive amination of the corresponding r-keto acid in the presence of a recombinant whole cell catalyst, bearing a leucine dehydrogenase and formate dehydrogenase. The desired L-neopentylglycine was obtained with >95% conversion and a high enantioselectivity of >99% ee at substrate concentrations of up to 88 g/L.

Characterization of a whole‐cell catalyst co‐expressing glycerol dehydrogenase and glucose dehydrogenase and its application in the synthesis of L‐glyceraldehyde

“…We succeeded in generating a catalyst which showed activities in a similar range fulfilling an important issue regarding an efficient application of the catalyst (Gröger et al, 2006b;Menzel et al, 2004). Apart from the successful expression of both genes other parameters play an important role for the applicability of the catalyst.…”

“…Gröger et al have compared the economy of isolated enzymes and whole-cells. Due to the more extensive procedures and the need of adding expensive cofactor to the isolated enzymes, the biotransformation with whole-cells is a cost-attractive alternative (Gröger et al, 2006b). Since GlyDH showed excellent enantioselectivity in the reduction of racemic glyceraldehyde (Richter et al, 2009), our primary focus was to transfer the kinetic resolution of racemic glyceraldehyde to the whole-cell system.…”

A Novel meso -Diaminopimelate Dehydrogenase from Symbiobacterium thermophilum: Overexpression, Characterization, and Potential for d -Amino Acid Synthesis

“…As such, many methods for the synthesis of D-amino acids and their derivatives have been developed. Just as L-amino acid dehydrogenases are useful for preparation of L-amino acids from the corresponding 2-keto acids (6,7,13,21), the use of D-amino acid dehydrogenase (D-AADH) should offer a straightforward approach, in which the enzyme catalyzes the reductive amination of 2-keto acid to give D-amino acid. However, NAD(P)H-dependent D-amino acid dehydrogenase is much less abundant in nature than its L-amino acid counterpart and largely unexplored.…”

Whole cell biotransformation for reductive amination reactions

“…33 l-leucine dehydrogenase, e.g., has been used for production of l-tertleucine and l-neopentylglycine. 34 Since amino acid dehydrogenases depend on NAD(P)H, cofactor recycling is required by coupling to formate dehydrogenase. 34 Transaminases, on the other hand, are often active with a broad spectrum of keto acids as substrates, but they require stoichiometric supply of an amino acid as amino group donor.…”

“…34 Since amino acid dehydrogenases depend on NAD(P)H, cofactor recycling is required by coupling to formate dehydrogenase. 34 Transaminases, on the other hand, are often active with a broad spectrum of keto acids as substrates, but they require stoichiometric supply of an amino acid as amino group donor. Amino acid dehydrogenases may be coupled with transaminases to enable reductive amination of many keto acids.…”