Related Experiment Videos
Proteinase inhibitory spectrum of mouse murinoglobulin and alpha-macroglobulin
K Abe1, K Yamamoto, H Sinohara
1Department of Biochemistry, Kinki University School of Medicine, Osaka.
Abstract:
The interactions of mouse murinoglobulin and alpha-macroglobulin with several proteinases were investigated by filtration and by assays of amidolytic activity towards synthetic substrates in the presence of proteinaceous enzyme inhibitors as well as assays of the inhibition of proteolytic activity. Mouse alpha-macroglobulin formed complexes with thrombin, clotting factor Xa, plasmin, pancreatic kallikrein, plasma kallikrein, submaxillary gland trypsin-like proteinase, neutrophil elastase, and pancreatic elastase. These complexes lost the proteolytic activities against high-molecular-weight substrates, but protected the active sites of the enzymes from inactivation by their proteinaceous inhibitors. Mouse murinoglobulin showed essentially the same properties except (i) that it did not form a complex with the clotting factor Xa, and (ii) that it did not protect plasma kallikrein, neutrophil elastase or submaxillary proteinase from inactivation by their proteinaceous inhibitors, although it formed complexes with these proteinases. No interaction was detected between Clostridium histolyticum collagenase and murinoglobulin or alpha-macroglobulin. These results indicate (i) that murinoglobulin has a proteinase-binding spectrum similar to that of alpha-macroglobulin, but is weaker in the ability to protect the bound proteinases from inactivation by the proteinaceous inhibitors than alpha-macroglobulin and (ii) that mouse alpha-macroglobulin has essentially the same inhibitory spectrum as the human homologue.
Insights
Mouse alpha-macroglobulin and murinoglobulin bind various proteinases. Alpha-macroglobulin offers better protection against inhibitors, showing similar inhibitory spectra to its human counterpart.
Area of Science:
- Biochemistry
- Proteomics
- Enzymology
Background:
- Alpha-macroglobulins are key regulators of protease activity in mammals.
- Understanding interactions between these proteins and various proteinases is crucial for deciphering protease regulation.
Purpose of the Study:
- To investigate the interaction profiles of mouse murinoglobulin and alpha-macroglobulin with a panel of proteinases.
- To compare the inhibitory capacities of these mouse proteins against their respective proteinase targets and human alpha-macroglobulin.
Main Methods:
- Filtration assays to detect complex formation between proteinases and macroglobulins.
- Amidolytic activity assays using synthetic substrates to assess enzyme activity.
- Assays evaluating the inhibition of proteolytic activity by proteinaceous inhibitors.
Main Results:
- Mouse alpha-macroglobulin formed complexes with eight tested proteinases, losing high-molecular-weight substrate activity but retaining active site protection from inhibitors.
- Mouse murinoglobulin interacted with seven proteinases but showed reduced protection against plasma kallikrein, neutrophil elastase, and submaxillary proteinase.
- No interaction was observed between either mouse protein and Clostridium histolyticum collagenase.
Conclusions:
- Murinoglobulin exhibits a broad proteinase-binding spectrum comparable to alpha-macroglobulin but with diminished protective capabilities against inhibitors.
- Mouse alpha-macroglobulin demonstrates an inhibitory spectrum largely consistent with its human homologue.