Aldolase rabbit muscle

R)-2-Hydroxy-3-thiopropanal (Table 5), which could not be isolated from the reaction mixture, can be directly converted into 6-thio-D-wnimo-2-hexulose (7%) and 6-thio-L-xylo-2-hexulose (93 %) via rabbit muscle aldolase catalyzed condensation with dihydroxyacetonephos-phate28. 

The class I FruA isolated from rabbit muscle aldolase (RAMA) is the aldolase employed for preparative synthesis in the widest sense, owing to its commercial availability and useful specific activity of 20 U mg . Its operative stability in solution is limiting, but the more robust homologous enzyme from Staphylococcus carnosus has been cloned for overexpression [87], which offers unusual stability for synthetic purposes. Recently, it was shown that less polar substrates may be converted as highly concentrated water-in-oil emulsions [88]. 

Ozawa, H. (1967) Bridging reagent for protein. II. The reaction of N,N -polymethylenebis(iodoacetamide) with cysteine and rabbit muscle aldolase./. Biochem. (Tokyo) 62, 531. 

RAMA rabbit muscle aldolase (fructose-1,6-bis-phosphate aldolase)... 

Zhang Z., Post C.B., Smith D.L. Amide hydrogen exchange determined by mass spectrometry application to rabbit muscle aldolase. Biochemistry 1996, 35, 779—791. 

Scheme 28. RAMA = Rabbit muscle aldolase TPI = Triose phosphate isomerase...

These enzymes have been found in all plant and animal tissues examined and are absent only from a few specialized bacteria. Three closely related isoenzymes are found in vertebrates.185 186 The much studied rabbit muscle aldolase A is a 158-kDa protein tetramer of identical peptide chains.186 187 Aldolase B, which is lacking in hereditary fructose intolerance, predominates in liver and isoenzyme C in brain.185... 

Isolation and structure of eucomin and eucomol. Tetrahedron Lett 36 3479 Borysenko CW, Spaltenstein A, Straub JA, Whitesides GM (1989) The synthesis of aldose sugars from half-protected dialdehydes using rabbit muscle aldolase. J Am Chem Soc 111 9275... 

Scheme 5.22. Chemoenzymatic synthesis of (+) exo-breviocomin by rabbit muscle aldolase (RAMA). Pase = phosphatase.

Schmid, W, Whitesides, G, A new approach to cyclitols based on rabbit-muscle aldolase (RAMA), J. Am. Chem. Soc., 112, 9670-9671, 1990. 

Effenberger and coworkers reported a de novo approach to 5-thio-D-f/zreo-2-pentulofuranose (5-thio-D-xylulose, 20) (Figure 9.7) from 2-mercaptoacetaldehyde, employing rabbit muscle aldolase (RAMA EC 4.1.2.13) and yeast transketolase (EC 2.2.1.1) as the catalysts [32]. 

Hung, R R, Straub, J A, Whitesides, G M, a-Amino aldehyde equivalents as substrates for rabbit muscle aldolase s3mthesis of l,4-dideoxy-l,4-imino-D-arabinitol and 2(R),5(R)-bis(hydroxy-methyl)-3(R),4(R)-dihydrox3fpyrrolidine, J. Org. Chem., 56, 3849-3855, 1991. 

The enzymatic aldol reaction represents a useful method for the synthesis of various sugars and sugar-like structures. More than 20 different aldolases have been isolated (see Table 13.1 for examples) and several of these have been cloned and overexpressed. They catalyze the stereospecific aldol condensation of an aldehyde with a ketone donor. Two types of aldolases are known. Type I aldolases, found primarily in animals and higher plants, do not require any cofactor. The x-ray structure of rabbit muscle aldolase (RAMA) indicates that Lys-229 is responsible for Schiff-base formation with dihydroxyacetone phosphate (DHAP) (Scheme 13.7a). Type II aldolases, found primarily in micro-organisms, use Zn as a cofactor, which acts as a Lewis acid enhancing the electrophilicity of the ketone (Scheme 13.7b). In both cases, the aldolases accept a variety of natural (Table 13.1) and non-natural acceptor substrates (Scheme 13.8). 

D-Fructose-1,6-diphosphate aldolase (FDP) catalyzes the reversible aldol addition of DHAP and D-glyceraldehyde-3-phosphate (G3P) to form D-fructose-1,6-diphosphate (FDP), for which Keq 10 M in favor of FDP formation (O Scheme 6). Rabbit muscle aldolase accepts a wide range of aldehyde acceptor substrates with DHAP as the donor to generate 35, 45 vicinal diols, stereospecifically (O Scheme 5). A racemic mixture of non-natural aldehyde acceptors can be partially resolved only under conditions of kinetic control. When... 

Access to thioketoses with sulfur in the ring could also conveniently be provided by an aldolase-based strategy. This involves rabbit muscle aldolase catalyzed carbon-carbon bond... 

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