What are the possible effects of export (secretion, using a pMAL-p5 vector) on solubility/stability of the fusion?
Initiating export through the cytoplasmic membrane puts a fusion protein on a different folding pathway – a difference in the solubility or stability of the protein is determined by whether this folding pathway leads to a different 3-dimensional structure for the protein. Some proteins, like MBP itself, can fold properly either in the cytoplasm or when exported to the periplasm. However, the normal folding pathway for some proteins is incompatible with passage through the membrane. In these cases, the fusion protein gets stuck in the membrane and cannot fold properly, which can lead to its degradation (17).
