Limited proteolysis of the alpha-macroglobulin rat alpha 1-inhibitor-3. Implications for a domain structure.
Rat alpha 1-inhibitor-3 is a 180-kDa monomeric proteinase inhibitor found in high concentration in rat plasma. By several criteria it has been shown to be a member of the family of alpha-macroglobulin proteinase inhibitors often exemplified by the tetrameric human alpha 2-macroglobulin. We have used limited proteolysis of rat alpha 1-inhibitor-3 to probe the domain structure of this family of proteins. Proteinases of different specificities, including trypsin, chymotrypsin, thermolysin, and Staphylococcus aureus V8 proteinase, were employed and a common fragmentation pattern was observed when the reaction products were examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. These fragments were electrotransferred to polyvinylidene difluoride membranes and subjected to NH2-terminal amino acid sequence analysis in order to position them within the context of the primary structure. The fragmentation pattern may define the domain structure of alpha 1-inhibitor-3 and serve as a model for the domain organization of the family of alpha-macroglobulin proteinase inhibitors.
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Related Subject Headings
- alpha-Macroglobulins
- Trypsin
- Thermolysin
- Rats
- Protease Inhibitors
- Peptide Mapping
- Peptide Fragments
- Papain
- Molecular Weight
- Molecular Sequence Data
Citation
Published In
ISSN
Publication Date
Volume
Issue
Start / End Page
Location
Related Subject Headings
- alpha-Macroglobulins
- Trypsin
- Thermolysin
- Rats
- Protease Inhibitors
- Peptide Mapping
- Peptide Fragments
- Papain
- Molecular Weight
- Molecular Sequence Data