Study on the Function of Tumor Necrosis Factor α Before and After Mutation in Hepatitis B.

BACKGROUND/AIMS: To explore the cause of functional changes of TNF-α in removing hepatitis B virus (HBV) through the structural changes of each site in TNF-α before and after mutation.

METHODOLOGY: Three typical mutant sites (TNF-α-308G/A, 857C/T and 863C/A of TNF-α) were chosen and methods like ab initio modeling was adopted for 3D modeling of TNF-α before and after mutation. The structural changes were also analyzed. Then structural changes and functional changes were brought together for comparison to infer the root cause of the changes.

RESULTS: Mutation of TNF-α-308G/A led to the production of multiple helical structures and that of 863C/A caused the production of one helical structure in its adjacent region. Mutation of 857C/T, however, did not cause the change in the basic structure of TNF-α.

CONCLUSIONS: The helical structure of TNF-α may have a positive effect on the removal of hepatitis B virus.