Autocatalytic processing of procathepsin E to cathepsin E and their structural differences.
The processing of human gastric procathepsin E to its mature form, cathepsin E, was studied at pH 3.5. The results revealed the autocatalytic and apparently one-step conversion of procathepsin E to cathepsin E within 10 min of incubation at 14 degrees C under the conditions used. Analyses of the amino acid sequences of both procathepsin E and cathepsin E showed that cleavage occurred at the Met36-Ile37 bond to produce the mature form, cathepsin E. The NH2-terminal amino acid sequence of procathepsin E thus determined was identical with that predicted from the cDNA sequence by Azuma et al. except that the NH2-terminal glutamine residue in the latter was converted into a pyroglutamic acid residue in the former and that the glycine residue at position 2 in the latter sequence was deleted in the former. On the other hand, the NH2-terminal amino acid sequence of cathepsin E was identical with that reported previously by us.
Athauda
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SB
Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo, Japan.
Takahashi
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T
Kageyama
T
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Takahashi
K
K
D000595:Amino Acid Sequence; D020059:Cathepsin E; D002403:Cathepsins / Q000235:genetics* / Q000378:metabolism; D004247:DNA / Q000235:genetics; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000235:genetics* / Q000378:metabolism; D005753:Gastric Mucosa / Q000201:enzymology; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D012689:Sequence Homology, Nucleic Acid
D004792:Enzyme Precursors; D004247:DNA; D002403:Cathepsins; C067581:procathepsin E; D020059:Cathepsin E