Exothermic effects observed upon heating of [beta.sub.2]-microglobulin monomers in the presence of amyloid seeds

The effects of heat on the acid-unfolded monomer at pH 2.5 were studied to understand the initial stages in the formation of amyloid fibrils of [beta.sub.2]-microglobulin ([beta]2-m), a protein responsible for dialysis-related amyloidosis. It was found that moderate heat treatment of [beta]2-m in the presence of seed fibrils results in an exothermic sigmoidal transition leading to a conformational state and may be interpreted in terms of the effects of heat associated with the formation, the association and unfolding of fibrils.