BACKGROUND: @entity4483 is a dimeric protein that can form tetramers, hexamers and higher order oligomers. These forms have been suggested to play a role in @entity5764 activation. METHODOLOGY/PRINCIPAL FINDINGS: Oligomerization was found to require a low molecular weight trigger/cofactor and could not be detected for highly pure dimer, irrespective of handling. @entity14615 was identified as a substance that can serve this role. Oligomerization is dependent on both the @entity14615 concentration and pH, with optima around 90 mM @entity14615 and pH 7, respectively. No oligomerization was observed above pH 8, thus the protonated form of @entity14615 is the active species in promoting assembly of dimers to higher species. However, @entity1520 bonds are not involved and the process is independent of redox potential. The process was also found to be independent of whether @entity141 is bound to the protein or not. Tetramers that are purified from dimers and @entity14615 by gel filtration are kinetically stable, but dissociate into dimers upon heating. Dimers do not revert to tetramer and higher oligomer unless @entity14615 is again added. Both tetramers and hexamers bind the target peptide from @entity876 with retained stoichiometry of one peptide per @entity4483 monomer, and with high affinity (lgK=7.3  0.2 and 7.2  0.2, respectively in 10 mM BisTris, 5 mM CaCl(2), pH 7.0), which is less than one order of magnitude reduced compared to dimer under the same buffer conditions. CONCLUSION/SIGNIFICANCE: @entity4483 oligomerization requires protonated @entity14615 as a trigger/cofactor. Oligomers are kinetically stable after @entity14615 is removed but revert back to dimer if heated. The results underscore the importance of kinetic versus thermodynamic control of @entity4483 @entity6960 .

Molecular determinants of XXXX oligomer formation.

@entity5764 :: ('101669765', 'Gene') :: ['RAGE'] @entity4483 :: ('6285', 'Gene') :: ['S100B'] @entity876 :: ('7157', 'Gene') :: ['p53'] @entity6960 :: ('MESH:D001796', 'Disease') :: ['protein aggregation'] @entity1520 :: ('CHEBI:48343', 'Chemical') :: ['disulfide'] @entity14615 :: ('CHEBI:16069', 'Chemical') :: ['imidazol', 'Imidazol'] @entity141 :: ('CHEBI:29108', 'Chemical') :: ['Ca(2+)']
@entity4483 :: (6285,Gene) :: ['S100B']
