Test ID: TPPTF
Tripeptidyl Peptidase 1 (TPP1) and Palmitoyl-Protein Thioesterase 1 (PPT1), Fibroblasts
Method Description
Describes how the test is performed and provides a method-specific reference
The synthetic substrate for palmitoyl-protein thioesterase 1 (PPT1) is 4-methylumbelliferyl-6-thioplamitoyl-beta-glucoside. The fibroblasts are homogenized. Approximately 10 mcg of protein is combined with substrate and incubated at 37 degrees C for 1 hour. The reaction is stopped with a glycine buffer. The fluorescence of the 4-methylumbelliferone product is read using a fluorescence plate reader and activity is calculated based on amount of product formed during the 1 hour incubation period.(Van Diggelen OP, Keulemans JLM, Winchester B, et al: A rapid fluorogenic palmitoyl-protein thioesterase assay: Pre and post natal diagnosis of INCL. Mol Genet Metab 1999;66:240-244)
The synthetic substrate tripeptidyl peptidase 1 (TPP1) is Ala-Ala-Phe-7-amino-4-methylcoumarin. The fibroblasts are homogenized. Approximately 5 mcg of protein is combined with substrate and incubated at 37 degrees C for 1 hour. The reaction is stopped with a glycine buffer. The fluorescence of the 7-amino-4-methylcoumarin product is read using a fluorescence plate reader and activity is calculated based on amount of product formed during the 1 hour incubation period.(Sohar I, Lin L, Lobel P: Enzyme-based diagnosis of classical late infantile neuronal ceroid lipofuscinosis: comparison of tripeptidyl peptidase I and pepstatin-insensitive protease assays. Clin Chem 2000;46:1005-1008)
Day(s) and Time(s) Test Performed
Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Thursday


