Disease relevance of CTSL1

• Z-Phe-Phe-CHN2, a selective inhibitor of cathepsin L, at 1, 5, and 10 microM, inhibited bone resorption by rat osteoclasts 50, 85, and 100 per cent and, in chicken osteoclasts, cathepsin L activity was comparably inhibited [1].

High impact information on CTSL1

• Like the analogous diazomethyl ketones 4 and 5, these inhibitors were also found to inactivate cathepsin L in common with other inhibitors under current investigation [2].
• The complete amino acid sequence of cathepsin L has been determined and consists of 215 residues [3].
• Cathepsin L exhibited a single band of Mr 27,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions, presented a high affinity for the substrate Z-Phe-Arg-NMec, was very unstable at neutral pH, and was inhibited by Z-Phe-Phe-CHN2 [3].
• Cathepsin L was purified from chicken liver lysosomes by a two-step procedure [3].
• Ki values for the inhibition of cysteine proteinases were as follows: papain (less than 1 X 10(-11)M), cathepsin B (8 X 10(-10)M), cathepsin H (about 2 X 10(-8)M) and cathepsin L (about 3 X 10(-12)M) [4].

Biological context of CTSL1

• The highest sequence homology is observed between rat cathepsin H and chicken cathepsin L. As shown by X-ray studies, papain and actinidin have a clearly defined double domain structure [5].

Associations of CTSL1 with chemical compounds

• Chicken cathepsin L accepts proline residues in all positions except P'1 [6].

Analytical, diagnostic and therapeutic context of CTSL1

• Antibodies, raised in chickens (IgY) and rabbits (IgG) against the lysosomal proteinase cathepsin L, targeted the enzyme in an ELISA and Western blot [7].
• The secondary structure of the recently sequenced chicken liver cathepsin L (EC 3.4.22.15) has been studied both by circular dichroism and a predictive method [8].

References