Serpin structure, mechanism, and function

Serpin... At the level of protein biosynthesis and folding, the serpin fold represents a fine balance between conflicting needs of, one one hand, features that are needed to direct metastable folding and the ability to undergo facile conformational interconversions as part of the normal mechanism of proteinase inhibition, and on the other hand, the avoidance of inappropriate or premature inactivation through coversion to the latent state or through polymerization. That this is a fine balance illustrated by the many spontaneous single point mutations in many serpins.