MenD as a versatile catalyst for asymmetric synthesis

Systematic Analysis of Large Enzyme Families: Identification of Specificity‐ and Selectivity‐Determining Hotspots

“…Carboligation of aketoglutarate with benzaldehyde resulted (upon decarboxylation) in the formation of (R)-5-hydroxy-4-oxo-5-phenylpentanoate with > 93 % ee. [37] To allow for binding of benzaldehyde in the S-pocket, two positions were exchanged, that is, F475 and I474 (standard numbers 477 and 476, respectively). As a result, the S-pocket of the double variant I474A/F475G was accessible for benzaldehyde as acceptor, [35] and the high R selectivity of the wildtype enzyme was switched to (S) enantioselectivity (75 % ee).…”

Diversität asymmetrischer Thiamin-Katalyse

“…Genannt sei als Beispiel MenD, das eine konjugate Addition nach Art der Stetter-Reaktion katalysiert (AG Sprenger, Universität Stuttgart). MenD führt eine 1,4-Addition an eine Ringstruktur durch, die weder Aldehyd-noch Ketonfunktion aufweist [11].…”

New Stetter reactions catalyzed by thiamine diphosphate dependent MenD from E. coli

“…2.2.1.9) catalyzes as a physiological reaction a Stetter-like addition of (decarboxylated) ␣-ketoglutarate to isochorismate (1) ultimately resulting in the formation of SHCHC (2) (Jiang et al, 2007;Dawson et al, 2008Dawson et al, , 2010) (Scheme 1C). MenD from Escherichia coli K12 and Bacillus subtilis has been described and analyzed in detail for its carboligation activity, especially with respect to asymmetric 1,2-additions (Kurutsch et al, 2009;Westphal et al, 2013aWestphal et al, , 2013bWestphal et al, , 2014. MenD is highly specific for its physiological donor substrate ␣-ketoglutarate, but has a broad substrate range with respect to the acceptor aldehydes in 1,2-additions.…”

“…MenD is highly specific for its physiological donor substrate ␣-ketoglutarate, but has a broad substrate range with respect to the acceptor aldehydes in 1,2-additions. This, however, is different for the Stetter-type addition of decarboxylated ␣-ketoglutarate: in addition to its physiological substrate isochorismate, (2S,3S)-2,3-dihydroxy-2,3-dihydrobenzoate (2,3-trans-CHD, 3) and its carboxymethyl ether derivative 5 are the only known alternative acceptor substrates (Kurutsch et al, 2009;Fang et al, 2010Fang et al, , 2011 …”

“…Expression of menD in E. coli BL21(DE3) and purification of the C-terminally hexahistidine-tagged enzyme was performed as described previously (Kurutsch et al, 2009;Beigi et al, 2013aBeigi et al, , 2013b. The pure protein was obtained by Ni-affinity chromatography.…”