A NEW METHOD FOR THE DETECTION OF HYDANTOINASES WITH RESPECT TO THEIRENANTIOSELECTIVITY ON ACRYLAMIDE GELS BASED ON ENZYME-ACTIVITY STAIN

A new and highly sensitive method was developed for the identification of hydantoinases on acrylamide gels. For this purpose, cell-lysates f rom different natural isolates are subjected on PAGE under non-denatur ating conditions. The respective localisation of the hydantoinase is o btained by in situ product precipitation during the reverse enzyme rea ction: in contrast to the used substrate (N-carbamoyltryptophan), the product (indolylmethylhydantoin) is barely soluble and gives a dense p recipitation dot caused by crystallisation of the product inside of th e polyacrylamide gel at the position corresponding to the location of the enzyme. This method can also be used for the subsequent differenti ation between L- and D-selective hydantoinases, since L- or D-carbamoy ltryptophan is used as substrate.