Complex systems protein folding

For the first group (i.e. intracellular soluble enzymes and proteins), which need no posttranslational modification and complex domain organization influencing protein folding, E. coli is the most preferred choice. However, for the other targets, alternative expression systems often provide a higher rate of success. The most common expression systems are presented in this chapter. 

Self-organization systems under thermodynamic control (spontaneous processes with a negative free-energy change), such as supramolecular complexes, crystallization, surfactant aggregation, certain nano-structures, protein folding, protein assembly, DNA duplex. 

Protein folding is a complex, trial and error process that can sometimes result in improperly folded molecules. These misfolded proteins are usu ally tagged and degraded within the cell (see p. 441). However, this qual ity control system is not perfect, and intracellular or extracellular aggregates of misfolded proteins can accumulate, particularly as individ uals age. Deposits of these misfolded proteins are associated with a number of diseases including amyloidoses. 

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