Purification and properties of malyl-coenzyme A lyase from Pseudomonas AM1.
1. Malyl-CoA lyase was purified 20-fold from extracts of methanol-grown Pseudomonas AM1. 2. Preparations of the enzyme were essentially homogeneous by electrophoretic and ultracentrifugal criteria. 3. Malyl-CoA lyase has a molecular weight of 190000 determined from sedimentation-equilibrium data. 4. Within the range of compounds tested, malyl-CoA lyase is specific for (2S)-4-malyl-CoA or glyoxylate and acetyl-CoA or propionyl-CoA. 5. A bivalent cation is essential for activity, Mg(2+) or Co(2+) being most effective. 6. Malyl-CoA lyase is inhibited by (2R)-4-malyl-CoA and by some buffers, but thiol-group inhibitors are without effect. 7. Optimal activity was recorded at pH7.8. 8. An equilibrium constant of 4.7x10(-4)m was determined for the malyl-CoA cleavage reaction. 9. The Michaelis constants for the enzyme are: 4-malyl-CoA, 6.6x10(-5)m; acetyl-CoA, 1.5x10(-5)m; glyoxylate, 1.7x10(-3)m; Mg(2+), 1.2x10(-3)m.
D002499:Centrifugation, Density Gradient; D002848:Chromatography, DEAE-Cellulose; D003035:Cobalt / Q000378:metabolism; D003065:Coenzyme A; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D008293:Malates; D008970:Molecular Weight; D007652:Oxo-Acid-Lyases / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D011549:Pseudomonas / Q000201:enzymology*; D014461:Ultracentrifugation
D008293:Malates; D003035:Cobalt; D007652:Oxo-Acid-Lyases; D008274:Magnesium; D003065:Coenzyme A