Hydantoinases and related enzymes as biocatalysts for the synthesis of unnatural chiral amino acids

A cascade of hydantoinase, N-carbamoylase and hydantoinracemase can be used for the production of natural and unnatural chiral D- and L-amino acids fr om chemically synthesized hydantoin derivatives. Potentially, 100% conversi on and 100% optically pure amino acids can be obtained at the same time if racemic substrates are used. Recent research activities concentrate on newl y isolated or improved enzymes and include directed evolution techniques, s tructure elucidation, studies of fusion proteins and the use of specially d esigned whole cell biocatalysts.