  We study the thermodynamic and kinetic consequences of the competition
between single-protein folding and protein-protein aggregation using a
phenomenological model, in which the proteins can be in the unfolded (U),
misfolded (M) or folded (F) states. The phase diagram shows the coexistence
between a phase with aggregates of misfolded proteins and a phase of isolated
proteins (U or F) in solution. The spinodal at low protein concentrations shows
non-monotonic behavior with temperature, with implications for the stability of
solutions of folded proteins at low temperatures. We follow the dynamics upon
"quenching" from the U-phase (cooling) or the F-phase (heating) to the
metastable or unstable part of the phase diagram that results in aggregation.
We describe how interesting consequences to the distribution of aggregate size,
and growth kinetics arise from the competition between folding and aggregation.
