Peroxisomal localization of serine:pyruvate aminotransferase in human liver

The distribution of L-serine:pyruvate aminotransferase (EC 2.6.1.51) in human liver was examined by centrifugation in a sucrose density gradient. The enzyme was located only in the peroxisomes and in the soluble fraction. The peroxisomal and soluble enzymes were highly purified and characterized. The two enzyme preparations had nearly identical properties, suggesting that the soluble enzyme is from broken peroxisomes. The two enzyme preparations showed different properties from rat liver serine:pyruvate aminotransferase (Noguchi, T., Okuno, E., and Kido, R. (1976) Biochem. J. 159, 607-613).