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Human tumor necrosis factor. Production, purification, and characterization
The Journal of Biological Chemistry
|February 25, 1985
Summary
Researchers purified human tumor necrosis factor (TNF) from leukemia cell cultures. This study details the purification process and characterizes TNF, revealing its molecular weight and homology to lymphotoxin.
Area of Science:
- Biochemistry
- Immunology
- Molecular Biology
Background:
- Human tumor necrosis factor (TNF) is a key cytokine involved in inflammation and immunity.
- Understanding TNF's properties is crucial for developing targeted therapies.
Purpose of the Study:
- To purify human TNF to homogeneity from HL-60 cell line supernatants.
- To characterize the biochemical and physical properties of purified human TNF.
- To investigate the sequence homology between TNF and lymphotoxin.
Main Methods:
- Purification using controlled-pore glass, DEAE-cellulose, Mono Q FPLC, and reverse-phase HPLC.
- Homogeneity assessment via SDS-PAGE and N-terminal sequence analysis.
- Biochemical characterization including molecular weight, isoelectric point, and disulfide bridge analysis.
- Amino acid sequence comparison with lymphotoxin.
Main Results:
- Successfully purified homogeneous human TNF with a specific activity of ~10^8 units/mg.
- Determined molecular weight of ~17,000 Da, isoelectric point of 5.3, and presence of a disulfide bridge.
- Identified approximately 50% homology between TNF and lymphotoxin based on sequence analysis.
Conclusions:
- Established a robust purification protocol for human TNF.
- Provided detailed characterization of purified TNF, essential for further functional studies.
- Demonstrated significant sequence homology between TNF and lymphotoxin, suggesting related functions or evolutionary origins.