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Abstract
An enzyme that catalyzes the synthesis of ceramide and its degradation to sphingosine and fatty acid has been found in pig lens epithelium. The enzyme has been partially purified fivefold by subcellular fractionation. It is activated by Triton X-100 and sodium cholate. The pH optimum for both hydrolase and synthetase has occurred at alkaline range. The enzymatic hydrolysis of ceramide has an apparent Km of 1.0 x 10(-4) M, and its reverse reaction (via the free-acid pathway) has an apparent Km of 8.2 X 10(-5) M and 2.45 X 10(-4) M for palmitic acid and sphingosine, respectively. The hydrolysis of ceramide by this enzyme was stimulated approximately 75% in the presence of fatty acid-free bovine serum albumin at the concentration of 3.33 X 10(-5) M.