Identification of interleukin-8 converting enzyme as cathepsin L
| Autor: | Emiko Sano, Kensaku Ohashi, Masanobu Naruto, Toshio Nakaki |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Neutrophils
Cathepsin L Blotting Western Biophysics Cathepsin E Biology Biochemistry Cathepsin A Cathepsin B Analytical Chemistry Cathepsin O Cathepsin H Cathepsin L1 Humans Protein Precursors Molecular Biology Cells Cultured Chromatography High Pressure Liquid Cathepsin Chemotaxis Interleukin-8 Fibroblasts Molecular biology Cathepsins Culture Media Cysteine Endopeptidases Liver biology.protein Protein Processing Post-Translational |
| Zdroj: | Biochimica et biophysica acta. 1649(1) |
| ISSN: | 0006-3002 |
| Popis: | IL-8 is produced by various cells, and the NH2-terminal amino acid sequence of IL-8 displays heterogeneity among cell types. The mature form of IL-8 has 72 amino acids (72IL-8), while a precursor form (77IL-8) of IL-8 has five additional amino acids to the 72IL-8 NH2-terminal. However, it has been unclear how IL-8 is processed to yield the mature form. In this study, converting enzyme was purified as a single 31-kDa band on silver-stained polyacrylamide gel from 160 l of cultured fibroblast supernatant by sequential chromatography. NH2-terminal amino acid sequence analysis revealed a sequence, EAPRSVDWRE, which was identified as a partial sequence of cathepsin L. Polyclonal antibodies raised against cathepsin L recognized the purified converting enzyme on Western blot. Moreover, human hepatic cathepsin L cleaved 77IL-8 between Arg5 and Ser6, which is the same cleavage site as the putative converting enzyme, resulting in 72IL-8 formation. These data indicate that the converting enzyme of the partially purified fraction of the human fibroblast culture supernatant was cathepsin L. Furthermore, 72IL-8 was sevenfold more potent than 77IL-8 in a neutrophil chemotaxis assay. These results show that cathepsin L is secreted from human fibroblasts in response to external stimuli and plays an important role in IL-8 processing in inflammatory sites. |
| Databáze: | OpenAIRE |
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