Anti-Cathepsin L/V/K/H Polyclonal Antibody for WB, IF/ICC, ELISA - P07711

Core Product Specifications and Parameters

Biological Background: Cathepsin L Function and Localization

• Procathepsin L (Cathepsin L1) is a lysosomal cysteine protease encoded by the CTSL gene, also known as major excreted protein (MEP). Alternative initiation produces isoforms with or without a signal peptide, leading to nuclear or lysosomal localization.
• Functions as a thiol protease critical for overall protein degradation in lysosomes, antigen processing, bone remodeling, and thyroid hormone release via thyroglobulin proteolysis.
• Extracellularly, it acts as a major elastin-degrading enzyme at neutral pH and generates endostatin from COL18A1, contributing to extracellular matrix remodeling during inflammation. Related references: PMID:10716919
• Facilitates host cell entry of coronaviruses (SARS-CoV, SARS-CoV-2) and Ebolavirus by proteolytically activating viral spike glycoproteins in lysosomes via a slow acid-activated route. Related references: PMID:16339146 PMID:18562523 PMID:32142651 PMID:16081529 PMID:26953343
• Regulates cell cycle progression by proteolytic processing of the CUX1 transcription factor; nuclear isoforms lacking the signal peptide cleave CUX1 to modulate gene expression. Related references: PMID:15099520
• Subcellular localization includes lysosomes, apical cell membranes, secretory vesicles (chromaffin granules), and the extracellular space; additionally found in the nucleus when translated from downstream start sites.
• Post-translationally modified by glycosylation and disulfide bond formation; synthesized as an inactive zymogen that is proteolytically processed to the mature active enzyme.

Experimental Guidance and Technical Tips

• The immunogen used corresponds to amino acids 114-333 of human Cathepsin L, a region within the mature protease domain, which may contribute to cross-reactivity with mouse and rat orthologs.
• For Western blotting (WB), the predicted molecular weight of the proform is approximately 38 kDa; however, mature processed forms may appear smaller. Include appropriate protease inhibitors during sample preparation.
• In immunofluorescence (IF/ICC), consider permeabilization conditions to detect lysosomal or nuclear pools, and validate localization with organelle markers.
• ELISA applications may require optimizing coating conditions and antibody dilution; use recombinant protein or peptide standards as positive controls.
• Due to alternative initiation, multiple isoforms may be present; verify band patterns in your cell or tissue system using appropriate controls.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio specializes in providing high-quality IVD raw materials and comprehensive sourcing solutions for diagnostic manufacturers, laboratories, and research institutes. For projects targeting cathepsin proteases or lysosomal pathways, we offer validated antibody pairs, optimized monoclonal/polyclonal antibodies, bulk ancillary reagents, and rare-target raw-material procurement to streamline your assay development from concept to clinic.