The major excreted protein of transformed mouse cells is an acid activable cysteine protease (1). In this paper, oxidized insulin B chain is shown to be a substrate for this protease. By isolation and analysis of the insulin B peptides generated by the protease, the bond specificity of this protease was determined. The bonds preferentially cleaved are glu13-a1a14, leu17-val18, and tyr26-thr27. No obvious preference for a specific amino acid was found in these studies. The bond specificity of this cysteine protease for oxidized insulin B chain has been compared with that of other proteases, and it is the same as that reported for cathepsin L, suggesting that the major excreted protein and cathepsin L may be the same protein.
|Original language||English (US)|
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - Aug 29 1986|
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology