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Structural characterization of porcine enteropeptidase
M Matsushima1, M Ichinose, N Yahagi
1First Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
The Journal of Biological Chemistry
|August 5, 1994
Summary
Researchers characterized porcine enteropeptidase, a key digestive enzyme. They identified its three-chain structure and elucidated the precursor
Area of Science:
- Biochemistry
- Enzymology
- Molecular Biology
Background:
- Enteropeptidase is crucial for intestinal digestion, activating pancreatic zymogens.
- Understanding its structure is key to elucidating digestive processes.
Purpose of the Study:
- To structurally characterize porcine enteropeptidase.
- To isolate and analyze the cDNA clone encoding the enzyme.
Main Methods:
- Purification of enteropeptidase from porcine duodenal mucosa.
- Isolation and sequencing of a cDNA clone.
- Analysis of amino acid sequences and structural homology.
Main Results:
- Enteropeptidase consists of three polypeptide chains: M, L, and H.
- A cDNA clone revealed a 1034-amino acid precursor.
- The H chain shows homology to lipoprotein receptor and complement components.
- The L chain is homologous to serine proteinase catalytic domains.
- A specific sequence (Arg885-Arg-Arg-Lys888) in the L chain is implicated in substrate specificity.
Conclusions:
- The study provides the first structural characterization of porcine enteropeptidase.
- The findings offer insights into the enzyme's catalytic mechanism and substrate recognition.
- The identified structural features contribute to understanding intestinal digestion and related disorders.