Human Recombinant Pro-dipeptidyl Peptidase I (Cathepsin C) Can Be Activated by Cathepsins L and S but Not by Autocatalytic Processing
| Autor: | Conni Lauritzen, Vito Turk, John Pedersen, Torben Halkier, Søren W. Dahl, Iztok Dolenc, Boris Turk |
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| Rok vydání: | 2001 |
| Předmět: |
Glycosylation
Cathepsin L Molecular Sequence Data Cathepsin D Cysteine Proteinase Inhibitors Biochemistry Catalysis Cathepsin C Cathepsin B Endopeptidases Animals Humans Cystatin A Amino Acid Sequence Cystatin B Cystatin C Chromatography High Pressure Liquid Cathepsin S Cathepsin Enzyme Precursors biology Chemistry Circular Dichroism Hydrolysis Cathepsins Cystatins Recombinant Proteins Enzyme Activation Cysteine Endopeptidases Chromatography Gel Mutagenesis Site-Directed biology.protein Cattle Chickens Protein Processing Post-Translational |
| Zdroj: | Biochemistry. 40:1671-1678 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi001693z |
| Popis: | Human dipeptidyl peptidase I was expressed in the insect cell/baculovirus system and purified in its active (rhDPPI) and precursor (pro-rhDPPI) forms. RhDPPI was very similar to the purified enzyme (hDPPI) with respect to glycosylation, enzymatic processing, oligomeric structure, CD spectra, and catalytic activity. The precursor, which was a dimer, could be activated approximately 2000-fold with papain. Cathepsin L efficiently activated pro-rhDPPI in vitro at pH 4.5 (k(app) approximately 2 x 10(3) min(-)(1) M(-)(1)), and two cleavage pathways were characterized. The initial cleavage was within the pro region between the residual pro part and the activation peptide. Subsequently, the activation peptide was cleaved from the catalytic region, and the latter was cleaved into the heavy and light chains. Alternatively, the pro region was first separated from the catalytic region. Cathepsin S was a less efficient activating enzyme. Cathepsin B and rhDPPI did not activate pro-rhDPPI, and the proenzyme was incapable of autoactivation. Incubation of both pro-rhDPPI and rhDPPI with cathepsin D resulted in degradation. Cystatin C and stefins A and B inhibited rhDPPI with K(i) values in the nanomolar range (K(i) = 0.5-1.1 nM). The results suggest that cathepsin L could be an important activator of DPPI in vivo and that cathepsin D and possibly the cystatins may contribute to DPPI downregulation. |
| Databáze: | OpenAIRE |
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