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Measuring Erythrocyte Complement Receptor 1 Using Flow Cytometry
Published on: May 19, 2020
RELATION OF A beta(1)-GLYCOPROTEIN OF HUMAN SERUM TO THE COMPLEMENT SYSTEM
H J Müller-Eberhard1, U Nilsson
1Department of Clinical Chemistry, University Hospital, Uppsala, Sweden.
The Journal of Experimental Medicine
|October 30, 2009
Summary
Human beta(1C)-globulin, a complement system protein, converts to inactive beta(1A)-globulin upon activation by immune complexes or zymosan. This study investigates its role in complement activity and stability.
Area of Science:
- Immunology
- Biochemistry
- Complement System
Background:
- Human serum contains beta(1C)-globulin, a protein with serological activity linked to the complement system.
- Beta(1A)-globulin is identified as the inactivated form of beta(1C)-globulin.
- Complement activation involves complex interactions between serum proteins and activators like immune precipitates or zymosan.
Purpose of the Study:
- To investigate the role of beta(1C)-globulin in the human complement system.
- To characterize the conversion of beta(1C)-globulin to beta(1A)-globulin.
- To assess the functional activity of purified beta(1C)-globulin and its interaction with complement components.
Main Methods:
- Incubation of fresh human serum with immune precipitates, soluble gamma-globulin aggregates, or zymosan at specified temperatures.
- Testing purified beta(1C)-globulin and beta(1A)-globulin for complement component activity using hemolytic assays.
- Assessing the stability of isolated beta(1C)-globulin at 37°C and its effect on limited complement systems.
Main Results:
- Beta(1C)-globulin was removed from serum upon incubation with immune precipitates or zymosan, converting to beta(1A)-globulin.
- Purified beta(1C)-globulin reconstituted hemolytic activity in guinea pig R(3) but not human R(3); beta(1A)-globulin was inactive.
- Isolated beta(1C)-globulin lost activity and converted to beta(1A)-globulin upon storage at 37°C; it enhanced complement-mediated hemolysis and stabilized EAC'(1, 4, 2).
Conclusions:
- Beta(1C)-globulin is an active component of the complement system, undergoing conversion to an inactive form (beta(1A)-globulin) upon activation.
- The study provides evidence for the functional role of beta(1C)-globulin in complement-mediated hemolysis and stabilization of immune complexes.
- Beta(1C)-globulin's instability at physiological temperatures contributes to its transient activity in the complement cascade.
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