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FURTHER STUDIES ON THE IDENTITY OF PRECIPITINS AND PROTEIN SENSITIZERS (ALBUMINOLYSINS)
1Division of Bacteriology of the Department of Medicine, Stanford University, California.
The Journal of Experimental Medicine
|October 30, 2009
Summary
Specific precipitates, like sensitized cells, bind complement (alexin) fractions. This suggests precipitins act as sensitizers, not just mechanical binders, unifying antibody function.
Area of Science:
- Immunology
- Biochemistry
Background:
- The study investigates alexin (complement) fixation by specific precipitates formed between proteins and antisera.
- Previous research outlined in introductory paragraphs provides context for these experiments.
Purpose of the Study:
- To analyze alexin fixation by specific precipitates.
- To determine the relationship between specific precipitates and complement fractions.
- To explore the functional role of precipitins in immune reactions.
Main Methods:
- Experiments involving the addition of dissolved, unformed proteins to specific antisera.
- Comparison of alexin fixation by specific precipitates with that of indifferent suspensions like kaolin.
- Analysis of complement fractions (mid-piece and end-piece) adsorption.
Main Results:
- Specific precipitates exhibit similar complement fraction binding to sensitized cells.
- Unlike indifferent suspensions, precipitates bind complement fractions in a specific manner.
- The fixation of alexin by precipitates appears to be non-mechanical, suggesting a sensitizing role.
Conclusions:
- Precipitates function as protein sensitizers, making foreign proteins susceptible to complement action.
- Visible precipitation is a secondary event due to colloidal properties and reaction conditions.
- Antibodies, including precipitins and agglutinins, may primarily function as sensitizers for complement-mediated reactions.
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