Engineering O‐Succinyl‐L‐Homoserine Mercaptotransferase for Efficient L‐Methionine Biosynthesis by Fermentation‐Enzymatic Coupling Route

Abstract

L-Methionine is the unique sulfur-containing amino acid essential for humans and animals, which is widely used in pharmaceutical, food and feed industries. Its green and efficient production has attracted a great deal of attention. Fermentation-enzymatic coupling route is regarded to be promising for L-methionine biosynthesis, while O-succinyl-L-homoserine mercaptotransferase (MetZ) is the key biocatalyst. Exploring and engineering of MetZ with ideal catalytic properties is highly desired. Herein, the MetZ from Chromobacterium violaceum (CvMetZ) was screened and through in silico analyses, potential beneficial amino acid residues both at the access channel and around the oxygen anion holes were anchored for site-saturation mutagenesis. The positive mutants were obtained with improved activity for L-methionine biosynthesis using O-succinyl-Lhomoserine (OSH) and methyl mercaptan as substrate. The best mutant was further applied for L-methionine production and supply of methyl mercaptan was optimized in a fed-batch approach. The conversion of 100 g/L OSH reached 92% with L-methionine yield of 62.6 g/L, which was well coupled with the OSH fermentation level.

Available Strategies for Improving the Biosynthesis of Methionine: A Review

“…By calculation, the cost of this new production process is slightly higher than that of chemical synthesis. 76 Tang et al 77 catalyzed the synthesis of methionine from OSH/OAH and methylmercaptan by introducing O-succinyl-L-homoserine mercaptotransferase using glucose as a precursor. 78 Through the construction of an OSH efficient cell factory, OSH production 79 can reach 120 g/L.…”

Balancing the AspC and AspA Pathways of Escherichia coli by Systematic Metabolic Engineering Strategy for High-Efficient l-Homoserine Production

“…As a valuable nonproteinogenic amino acid, l -homoserine also functions as a platform compound for synthesizing various essential compounds, including 2,4-dihydroxybutyric acid, spermidine, 1,4-oxane-5-carboxylic acid, 1,3-propanediol, and l -phosphinothricin (L-PPT) . Moreover, its derivatives (O-succinyl- l -homoserine and O-acetyl- l -homoserine) can be converted into l -methionine by using an efficient sulfhydrylase, providing an appealing alternative for large-scale industrial production of l -methionine. − In recent years, with the development of synthetic biotechnology, many efforts have been put into the engineering of microbial cell factories for highly efficient and economical l -homoserine productions, which has emerged as a promising alternative to chemical synthesis methods.…”

Synthesis of a versatile 1H-indene-3-carboxylate scaffold enabled by visible-light promoted Wolff rearrangement of 1-diazonaphthalen-2(1H)-ones

“…4 Among them, representative intramolecular approaches include Lewis acid catalyzed rearrangement of vinylcyclopropenes, 5 and transition metal-or Brønsted acid-catalyzed formal Friedel-Crafts cyclization of allyl and propargyl alcohols, 6 diaryl-1,3-dienes, 7 dihydrocinnamoyl-substituted heterocycles, 8 and ortho-alkenedecorated cinnamates. 9 Other intramolecular methods include reductive cyclization of alkynylbenzene derivatives, 10 oxidative cross-dehydrogenative-coupling reaction, 11 palladium catalyzed cascade reaction of o-alkynylbenzylidene ketones, 12 platinumcatalyzed sp 3 C-H activation, 13 ruthenium-catalyzed ring-closing metathesis, 14 organocatalyzed Morita-Baylis-Hillman reaction, 15 and coinage metal catalyzed carbene insertion reactions and carboalkoxylation of alkynes. 16 On the other hand, a variety of intermolecular approaches were also developed for preparation of the indene skeleton, which include transition-metal catalyzed formal cycloaddition of internal alkynes and allenes with carbonyl derivatives, 17 palladium-catalyzed domino carboiodination between iodoaryl alkenes and internal alkynes, 18 FeCl 3 -catalyzed cyclization reaction of N-benzylic sulfonamides with arylallenes and disubstituted alkynes, 19 copper-catalyzed arylative cyclization of arylalkynes with aromatic sulfonyl chlorides, 20 and photocatalytic sulfonylcarbocyclization of alkynes.…”