Studies on carboxylases. III. Determination of the Michaelis-Menten constant of tyrosine decarboxylase

Abstract

A study has been carried out on the irifluence of the variation in concentration of the substrate and the enzyni on the speed of reactiou of tyrosine decarboxylase produced by the Streptococcus Faecalis R, employing Warburg’s technique.

The dates obtained are in accordance with the equation of speed of Michaelis-Menten. Graphically and analytically the coi stant of Michaelis- Menten, Ks, has been calculated and amounts to 0,0012 M.

The signification of this constant as well as the different methods eniployed in calculating same and. in determinating the maximal speed, are discussed.