A specific enzymatic method for the determination of taurine

An enzymatic assay was developed for the quantitative determination of the amino acid taurine by following spectrophotometrically the oxidation of NADH using tauropine dehydrogenase. This enzyme was sufficiently purified from the shell adductor muscle of the ormer, Haliotis lamellosa, by a single-step isolation procedure on an ion-exchange column. The enzyme is highly specific for taurine. The quantitation of taurine is possible in the range of 1.6 to 100 nmol/ml; the assay time takes about 90 min. The method was successfully applied to the estimation of taurine in neutralized perchloric acid extracts of different muscles of various molluscs without further treatment. Correct quantitation of taurine is possible even in the presence of a 10-fold higher concentration of L-alanine.