Biocatalysis: A Status Report.

This review describes the status of the fields of biocatalysts and enzymes, as well as existing drawbacks, and recent advances in the areas deemed to represent drawbacks. Although biocatalysts are often highly active and extremely selective, there are still drawbacks associated with biocatalysis as a generally applicable technique: the lack of designability of biocatalysts; their limits of stability; and the insufficient number of well-characterized, ready-to-use biocatalysts. There has been significant progress on the following fronts: (a) novel protein engineering tools, both experimental and computational, have significantly enhanced the toolbox for biocatalyst development. (b) The deactivation of biocatalysts under various stresses can be described quantitatively via rational models. There are several cases of spectacular leaps of stabilization after accumulating all stabilizing mutations found in earlier rounds. The concept that stabilization against one type of stress commonly also stabilizes against other types of stress is now experimentally considerably better founded than a few years ago. (c) A host of developments of novel biocatalysts in the past few years, in part fueled by improved designability and improved methods of stabilization, has considerably broadened the toolbox for synthetic chemistry.