title: Reduction in antiviral activity of human interferon-gamma in acidic media with reference to structural change.
abstract: The fluorescence intensity of a unique tryptophan 36 in human interferon-gamma was drastically decreased below pH 4 with a concomitant decrease of antiviral activity. The region of residues 32-42 of human interferon-gamma was found by calculation to have a low hydrophobicity together with a high helical hydrophobic moment, and the net electric charge of this region having an amphiphilic helical structure changed significantly near pH 4. These results suggest that the region of residues 32-42 plays an important role in exhibiting antiviral activity.
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003588:Cytopathogenic Effect, Viral; D004563:Electrochemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007371:Interferon-gamma / Q000494:pharmacology / Q000502:physiology*; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000502:physiology; D012845:Sindbis Virus / Q000502:physiology; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship; D014364:Tryptophan
chemical_list: D011994:Recombinant Proteins; D007371:Interferon-gamma; D014364:Tryptophan