Lysosomal serine protease with tripeptidyl-peptidase I activity. May act as a non-specific lysosomal peptidase which generates tripeptides from the breakdown products produced by lysosomal proteinases. Requires substrates with an unsubstituted N-terminus. Defects in TPP1 are the cause of neuronal ceroid lipofuscinosis type 2 (CLN2). A form of neuronal ceroid lipofuscinosis. Neuronal ceroid lipofuscinoses are progressive neurodegenerative, lysosomal storage diseases characterized by intracellular accumulation of autofluorescent liposomal material, and clinically by seizures, dementia, visual loss, and/or cerebral atrophy. The lipopigment pattern seen most often in CLN2 consists of curvilinear profiles. Belongs to the peptidase S53 family. 2 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: Mitochondrial; Secreted; Secreted, signal peptide; Protease; EC 220.127.116.11
Molecular Function: endopeptidase activity; metal ion binding; peptidase activity; peptide binding; protein binding; serine-type endopeptidase activity; serine-type peptidase activity; tripeptidyl-peptidase activity
Biological Process: bone resorption; central nervous system development; epithelial cell differentiation; lipid metabolic process; lysosome organization and biogenesis; nervous system development; neuromuscular process controlling balance; peptide catabolic process; protein catabolic process; proteolysis
LTP: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.