Purity: > 90% by SDS - PAGE Format: Liquid. In Phosphate Buffered Saline (pH 7.4) containing 10% glycerol.. CTSL, also known as cathepsin L1, is a lysosomal cysteine protease expressed in most eukaryotic cells. It plays a major role in intracellular protein catabolism and is potent in degrading collagen, laminin, elastin, as well as alpha-1 protease inhibitor and other structural proteins of basement membranes. Recombinant mouse CTSL, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.