TABLE 2.
Molecular and catalytic properties of recombinant l-malyl-CoA lyase and β-methylmalyl-CoA lyase from C. aurantiacus
| Property | Recombinant l-malyl-CoA lyasea/β-methylmalyl-CoA lyase | |
|---|---|---|
| Substrates | erythro-β-Methylmalyl-CoA, l-malyl-CoA, glyoxylate, propionyl-CoA, acetyl-CoA | |
| Products | Glyoxylate, propionyl-CoA, acetyl-CoA, erythro-β-methylmalyl-CoA, l-malyl-CoA | |
| Specific activitiesa (μmol min−1 mg of protein−1) | 6.5 ± 0.1 (β-methylmalyl-CoA lyase); 2.3 ± 0.2 (l-malyl-CoA lyase); 0.50 ± 0.01 (propionyl-CoA condensation); 0.48 ± 0.01 (acetyl-CoA condensation) | |
| Apparent Km values (mM) | 0.089 ± 0.02 (β-methylmalyl-CoA); 0.061 ± 0.01 (l-malyl-CoA); 1.2 ± 0.6 (propionyl-CoA); 0.36 ± 0.15 (acetyl-CoA); 2.0 ± 0.5 (glyoxylate) | |
| pH optimum | 7.1 (55°C) | |
| Temperature optimum | 70°C | |
| Native molecular mass | 210 ± 20 kDa | |
| Subunit molecular mass | 38 kDa | |
| Suggested composition | α5 or α6 | |
| Catalytic numbersa (s−1; per hexamer) | 24.5 ± 0.4 (β-methylmalyl-CoA consumption); 8.8 ± 0.8 (l-malyl-CoA consumption); 1.9 ± 0.02 (glyoxylate consumption + propionyl-CoA); 1.8 ± 0.04 (glyoxylate consumption + acetyl-CoA) | |
| Specificity | erythro-β-Methylmalyl-CoA, 100%; l-malyl-CoA, 35 ± 1%; propionyl-CoA, 100%; acetyl-CoA, 96 ± 2%; succinyl-CoA, <1%; glyoxylate, 100%; oxaloacetate + propionyl-CoA, 11 ± 3%; oxaloacetate + acetyl-CoA, 22 ± 18%; pyruvate, <1% | |
| Influence of divalent cations (concn [mM]) | Mg2+ (4), 100%; Mg2+ (0), <2%; Mn2+ (4), 31%; Co2+ (4), 31%; Ni2+ (4), 12%; Ca2+ (4), 4% | |
| Inhibitor (concn [mM]) | EDTA (1), <2% |
a
Data obtained for recombinant l-malyl-CoA lyase.