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PubMed · 3977867

Human liver cathepsin L.

R W Mason·G D Green·A J Barrett
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Abstract

Cathepsin L was purified to apparent homogeneity from human liver obtained post mortem. It was necessary to treat the homogenate at pH 4.2 and 37 degrees C to release active enzyme. The purification procedure involved ion-exchange chromatography on carboxymethyl-Sephadex and the Mono S column of a Pharmacia fast-protein-liquid-chromatography system. The enzyme was found to consist of two polypeptide chains of Mr 25 000 and 5000. The larger chain was shown to contain the active-site cysteine residue. Human cathepsin L proved to be similar to the rat and rabbit enzymes in regard to kinetic constants for the substrate benzyloxycarbonylphenylalanylarginine 7-(4-methyl)coumarylamide and rates of inactivation by the active-site-directed reagents benzyloxycarbonylphenylalanylphenylalanyldiazomethane and benzyloxycarbonylphenylalanylalanyldiazomethane. Thus clear characteristics of cathepsin L are now emerging, and these should simplify the identification of the enzyme in other tissues and species.

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Cathepsin BCathepsin LCathepsinsChromatography, Ion ExchangeCysteine EndopeptidasesElectrophoresis, Polyacrylamide GelEndopeptidasesHumansKineticsLiverMolecular WeightPeptidesSubstrate SpecificityJournal Article

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R W Mason, G D Green, A J Barrett. 1985-02-15. Human liver cathepsin L.. https://doi.org/10.1042/bj2260233

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