UCH-L1 is a protein encoded by the UCHL1 gene which is approximately 24,8 kDa. UCH-L1 is localised to the cytoplasm, endoplasmic reticulum membrane and lipid-anchor. It is involved in the metabolism of proteins, CDK-mediated phosphorylation and removal of Cdc6, respiratory electron transport and ATP synthesis by chemiosmotic coupling. This protein falls under the peptidase C12 family. It’s involved both in the processing of ubiquitin precursors and of ubiquitinated proteins. It is a thiol protease that recognizes and hydrolyzes a peptide bond at the C-terminal glycine of ubiquitin. It also binds to free monoubiquitin and may prevent its degradation in lysosomes. UCH-L1 is expressed in neurons and cells of the diffuse neuroendocrine system and their tumors, it is also weakly expressed in the ovaries. Mutations in the UCHL1 gene result in autosomal Spastic Paraplegia and Parkinson disease. UCH-L1 is down-regulated in brains of both Parkinson disease and Alzheimer disease patients. STJ96177 was affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogen. This polyclonal antibody detects endogenous levels of UCH-L1 protein.