Threonine aldolase-catalyzed aldol reactions

T. Nishiyama, S.S. Mobile, T. Kajimoto, M. Node, Synthesis of thymine polyoxin C by using L-threonine aldolase-catalyzed aldol reaction. Heterocycles 71 (2007) 1397-1405. 

Fujii, M., Miura, T., Kajimoto, T., and Ida, Y., Facile S5mthesis of 3,4-dihydroxyprolines as an application of the L-threonine aldolase-catalyzed aldol reaction. Sunlett 2000, 7, 1046-1048. 

Threonine Aldolase-Catalyzed Aldol Reactions Using Giycine and an Aidehyde... 

Figure 10.45 Aldol reactions catalyzed in vivo by serine hydroxymethyl transferase and by threonine aldolases.

The metabolism of P-hydroxy-a-amino adds involves pyridoxal phosphate-dependent enzymes, dassified as serine hydroxymethyltransferase (SHMT) (EC 2.1.2.1) or threonine aldolases (ThrA L-threonine selective = EC 4.1.2.5, L-aHo-threonine selective = EC 4.1.2.6). Both enzymes catalyze reversible aldol-type deavage reactions yielding glycine (120) and an aldehyde (Eigure 10.45) [192]. 

PLP-dependent enzymes catalyze the following types of reactions (1) loss of the ce-hydrogen as a proton, resulting in racemization (example alanine racemase), cyclization (example aminocyclopropane carboxylate synthase), or j8-elimation/replacement (example serine dehydratase) (2) loss of the a-carboxylate as carbon dioxide (example glutamate decarboxylase) (3) removal/replacement of a group by aldol cleavage (example threonine aldolase and (4) action via ketimine intermediates (example selenocysteine lyase). 

The glycine-dependent aldolases are pyridoxal 5-phosphate dependent enzymes that catalyze the reversible aldol reaction, where glycine and an acceptor aldehyde form a (i-hydroxy-a-amino acid (Scheme 5.47).74 Serine hydroxymethyltransferases, SHMT (EC 2.1.2.1), and threonine aldolases, two types of glycine dependent aldolases, have been isolated. In... 

Scheme 2.196 Aldol reactions catalyzed by L-threonine aldolase...

Aldol reactions have been catalyzed by aldolases as well as by catalytic antibodies. For example, L-threonine aldolase was applied to C—C bond formation of an aldehyde with glycine. The resulting adduct could be further converted to a precursor of N-acetyl-4-deoxy-D-mannosamine, a potent inhibitor of N-acetylneuraminic acid synthetase (Fig. 10.39(a)). "... 

An antibody that mimics threonine aldolase, which uses pyridoxal as the cofactor to catalyze the aldol reaction of glycine with aldehydes, has also been reported. Antibody 10H2 catalyzed the retro-aldol reaction of jd-hydroxy-a-amino acid in the presence of pyridoxal [55]. 

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