Sarcosine Dehydrogenase from Pseudomonas putida: Purification and Some Properties

A sarcosine dehydrogenase was purified to homogeneity from cell free extract of Pseudomonas putida aerobically grown in a medium containing creatinine or betaine as the carbon and nitrogen sources. The enzyme catalyzed dehydrogenation of N-methyl derivatives of some amino acids but was inert toward dimethylglycine, betaine and choline. Phenazine methosulfate, 2, 6-dichlorophenol indophenol, methylene blue, meldora blue, nile blue and potassium ferricyanide served as electron carriers. The maximal activity was observed at pH 8.0–9.0. The Km and K_max values for sarcosine were 29 mm and 1.2 μmol/min/mg, respectively. The molecular weight was estimated to be about 170,000, presumably composed of four sub-units. Spectrophotometric and fluorometric analyses indicated that the enzyme was a flavoprotein.