title: Dissociation of recombinant tumor necrosis factor-alpha studied by gel permeation chromatography.
abstract: The structure of tumor necrosis factor-alpha (TNF-alpha) was studied using gel permeation chromatography. At an initial protein concentration of 0.4 mg/ml, the TNF-alpha exists as a compact trimer with a Stokes radius of 2.3 +/- 0.1 nm. This trimer dissociates as the protein concentration is decreased, and this dissociation is effected by pH. At the lower protein concentrations at pH 6.0 a species with a Stokes radius of 1.9 +/- 0.1 nm, possibly monomer, is evident. This species is not obvious at pH 7.0, but instead a species with a Stokes radius of 2.2 +/- 0.1 nm appears.
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002851:Chromatography, High Pressure Liquid; D006023:Glycoproteins / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000302:isolation & purification*; D012996:Solutions; D014409:Tumor Necrosis Factor-alpha
chemical_list: D006023:Glycoproteins; D046911:Macromolecular Substances; D011994:Recombinant Proteins; D012996:Solutions; D014409:Tumor Necrosis Factor-alpha