Carbon-carbon coupling in biotransformation.

Most research on carbon-carbon coupling biocatalysts is still carried out on aldolases and ketolases from carbohydrate metabolism; the emphasis of these studies is on the synthesis of optically active compounds. A major target is to avoid expensive starting materials and to broaden the range of possible products. Protein engineering provides the basis not only for significant improvements of known catalysts, but also for the de novo development of new enzymes.