Ppt1 Protein (Palmitoyl Protein Thioesterase 1) is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
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| Attribute |
Value |
| Protein Name |
Palmitoyl-Protein Thioesterase 1 |
| Gene |
PPT1 |
| UniProt ID |
P60617 |
| PDB Structure |
1B41, 2VSN |
| Molecular Weight |
34 kDa |
| Subcellular Localization |
Lysosomal lumen |
| Protein Family |
Palmitoyl-protein thioesterase family |
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PPT1 (Palmitoyl-Protein Thioesterase 1) is a lysosomal enzyme that catalyzes the removal of palmitate (C16:0) fatty acid chains from cysteine residues of proteins. This enzyme is essential for the degradation of palmitoylated proteins in lysosomes and plays crucial roles in neuronal function[1].
PPT1 is a 306-amino acid enzyme that is synthesized as a pre-proenzyme:
- Signal peptide: 27 aa (secretory pathway)
- Propeptide: Cleaved in lysosome
- Mature enzyme: 277 aa
PPT1 has been crystallized (PDB: 1B41):
- Fold: α/β hydrolase family
- Active site: Ser155, Asp276, His289 (catalytic triad)
- Active site pocket: Hydrophobic, accommodating palmitoyl groups
- N-linked glycosylation: Multiple sites in the mature enzyme
- Signal peptide cleavage: At position 27
- Propeptide cleavage: Lysosomal activation
PPT1 catalyzes the hydrolysis of thioester bonds:
Palmitoyl-protein + H₂O → Protein + Palmitate
This reaction is essential for:
- Lysosomal protein degradation
- Turnover of palmitoylated proteins
- Synaptic protein recycling
- Cellular lipid homeostasis
PPT1 prefers:
- S-acylated (palmitoylated) proteins
- Proteins with thioester-linked fatty acids
- Small to medium-sized substrates
PPT1 interacts with:
- Synaptic proteins: CSP, SNAP-25, GAP-43
- Ras family proteins: Depalmitoylation targets
- Lysosomal cathepsins: Degradation pathway
PPT1 mutations cause the most severe form of NCL[1]:
- Inheritance: Autosomal recessive
- Onset: 6-12 months
- Features: Developmental arrest, vision loss, seizures, rapid decline
- Progression: Fatal by 3-10 years
PPT1 deficiency leads to:
- Accumulation of palmitoylated proteins
- Ceroid lipofuscin accumulation
- Lysosomal dysfunction
- Progressive neuronal loss
- Symptomatic care only
- Anticonvulsants for seizures
- Supportive multidisciplinary care
- Enzyme replacement therapy: PPT1 enzyme delivery[2]
- Gene therapy: AAV-vector CNS delivery
- Substrate reduction therapy: Reducing accumulation
- Small molecule chaperones: Being investigated
The study of Ppt1 Protein (Palmitoyl Protein Thioesterase 1) has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- Vines DJ, et al. "Molecular genetics of the neuronal ceroid lipofuscinoses." Brain Res Bull. 2001;57(2):193-198.
- Trondle G, et al. "Enzyme replacement therapy for infantile neuronal ceroid lipofuscinosis." Pediatrics. 2022;149(3):2021052345.
- Hofmann SL, et al. "PPT1 deficiency leads to accumulation of palmitoylated proteins." J Biol Chem. 2002;277(44):41510-41516.
Last updated: March 2026