title: Polymerization of tobacco mosaic virus protein without and with hydrogen ion binding.
abstract: When tobacco mosaic virus (TMV) protein is polymerized at pH values above 7 in unbuffered solutions, either by raising temperature at constant ionic strength or by increasing ionic strength at constant temperature, a 20 S component is formed having bound only the very small amount of H+ ion supplied by the unpolymerized protein. When hydrogen ion is added by titration during polymerization so as to keep pH constant, as would occur automatically if a buffer were present, a 20 S component is formed with one H+ ion bound each for half of the subunits. Thus, a 20 S form with and a 20 S form without bound H+ ion exist. Furthermore, the 20 S form without bound H+ ion binds H+ ion when supplied by titration to produce a 20 S form with the same amount of bound H+ ion as when H+ ion is supplied during the polymerization.
mesh_terms: D006860:Hydrogen Bonding; D007526:Isoelectric Point; D009994:Osmolar Concentration; D011485:Protein Binding; D011522:Protons; D013696:Temperature; D014027:Tobacco Mosaic Virus; D014764:Viral Proteins
chemical_list: D011522:Protons; D014764:Viral Proteins