Sandbox 16

Alpha-lytic protease

Alpha-lytic protease (αlp) is a 198-aa extracellular bacterial serine protease produced by Lysobacter enzymogenes. The three-dimensional fold of αlp puts it in the same class as cymotrypsin, trypsin and other digestive serine proteases. However, unlike its thermodynamically stable homologs, αlp is stabilized by a large unfolding activation barrier. This kinetic stability optimizes the native state to survive under the harsh, proteolytic conditions in which it operates. Since the native state is less stable than both an intermediate and a completely unfolded state, αlp requires a pro region to facilitate folding by stabilizing the folding transition state as well as the native state. After folding, the pro region is proteolytically cleaved, leaving an active αlp kinetically trapped