Porcine kidney betaine aldehyde dehydrogenase: purification and properties.
Significant betaine aldehyde dehydrogenase activity was found in porcine kidney. The enzyme was purified 320-fold with an overall recovery of 11%. It had a specific activity of 115.8 nkats/mg protein and proved to be homogeneous by SDS-PAGE with a subunit molecular mass of 52 kDa. IEF studies showed three bands with pI values of 5.74, 5.68 and 5.58, respectively. The enzyme was stable in a pH range between 5.0 and 10.0 and the optimum pH was 9.5. The reaction is highly specific for NAD+ and betaine aldehyde, although acetaldehyde, butyraldehyde and glyceraldehyde can be used. Estimated values of Km at pH 8.0 and 25 degrees C were 127 microM for betaine aldehyde and 40 microM for NAD+. The reaction could not be reversed even at high glycine betaine concentrations. The enzyme was not activated by salts at high concentrations but it was salt tolerant-retaining 50% of maximal activity at 1.0 M K+ and Na+. It is inferred that salt tolerance is an essential property for an enzyme participating in the cellular synthesis of an osmoprotectant. Proline, glycerol, sucrose and mannitol had a little effect on the enzyme activity while glycine betaine had an inhibitory effect.
Guzman-Partida
A M
AM
Centro de Investigación en Alimentación y Desarrollo A.C., Hermosillo, Sonora, Mexico.
Valenzuela-Soto
E M
EM
D000445:Aldehyde Oxidoreductases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D000818:Animals; D050728:Betaine-Aldehyde Dehydrogenase; D002414:Cations, Monovalent / Q000494:pharmacology; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D008970:Molecular Weight; D009243:NAD / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology; D013379:Substrate Specificity; D013552:Swine
D002414:Cations, Monovalent; D009243:NAD; D012964:Sodium; D000445:Aldehyde Oxidoreductases; D050728:Betaine-Aldehyde Dehydrogenase; D011188:Potassium