|Family type peptidase||C89.001 - acid ceramidase precursor (Homo sapiens), MEROPS Accession MER0100794 (peptidase unit: 137-389)|
|Content of family||Peptidase family C89 contains a self-cleaving precursor protein.|
Identifier created: MEROPS 8.2 (4 August 2008)|
Acid ceramidase (EC 220.127.116.11) is a lysosomal enzyme that is synthesized as a precursor and is activated by cleavage into alpha and beta chains. Hydrolysis has been shown to be an autocatalytic activity (Shtraizent et al., 2008). The mature ceramidase hydrolyses the sphingolipid ceramide to sphingosine and a free fatty acid (Park & Schuchman, 2006).
|Active site residues||C137 R153 D156 |
|Active site||The catalytic Cys (Cys143) has been identified by site-directed mutagenesis. Mutation of Arg159 and Asp162 also prevented autoprocessing (Shtraizent et al., 2008). It is not known whether Cys143 is also the active site residue responsible for ceramidase activity in the mature enzyme .|
|Inhibitors||Methyl methanethiosulfonate has been shown to be inhibitory (Shtraizent et al., 2008).|
|Molecular structure||Although no tertiary structure has been solved, the active site Cys is at the N-terminus of the beta chain, which is characteristic of N-terminal hydrolases of clan PB.|