Purification and Properties of Sarcosine Oxidase fromCylindrocarpon didymumM–1

Abstract

Sarcosine oxidase was purified to homogeneity from the cell extract of Cylindrocarpon didymum M–1, aerobically grown in medium containing choline as the carbon source. The molecular weight of the enzyme was estimated to be 45,000 by gel filtration method and 48,000 by the sodium dodecylsulfate disc gel electrophoresis method. The enzyme exhibited an absorption spectrum with maxima at 277 and 450 run and shoulders at 370 and 470 nm. The anaerobic addition of sarcosine to the enzyme resulted in the disappearance of the peak at 450 nm. The enzyme contained one mol of covalently bound FAD per mol of enzyme. Enzyme activity was inhibited by Ag⁺, Cu²⁺, Hg²⁺, p-chloromercuribenzoate and iodoacetate. The enzyme oxidized sarcosine but was inert toward choline, betaine, dimethylglycine and N-methyl amino acids. Km and V_max values for sarcosine were 1.8 ihm and 26.2 μmol/min/mg, respectively. The enzyme catalyzed the following reaction: Sarcosine+O₂+H₂O→glycine +formaldehyde+H₂O₂.