WHAT ARE ENZYMES? 83 



vided his laccase preparations into three fractions of dif- 

 ferent manganese content, each with an activity distinctly 

 proportional to the amount of manganese present. As 

 further proof of the importance of this manganese, he 

 was able to show that a minute addition of a salt of man- 

 ganese (manganese sulphate) increased the activity of 

 the laccase, whereas other metals had no such effect. 

 This led him to the dual conception of an enzyme, also 

 advocated by Armstrong: one of the constituents is ca- 

 pable of producing, to a slight degree, on its own account, 

 the chemical reaction associated with the particular enzyme 

 in question, but requires its activity to be augmented by 

 the presence of another substance inactive in itself 

 before its action becomes appreciable. The former may 

 consist of acid, alkali, calcium or magnesium salt, etc. 

 The latter component is more complex, usually protein- 

 like (egg-white, for example), and colloidal. 



Bertrand's views perhaps, also, Fischer's colossal work 

 on the synthesis of proteins from amino acids has led 

 the school of enzyme chemistry to shift its ground con- 

 siderably. Why these laborious, and always futile at- 

 tempts to isolate a pure enzyme from the cell ? Why not 

 attempt to synthesize one from simple inorganic and 

 organic materials? Trillat, in 1904, prepared a mixture 

 of traces of manganese chloride and egg albumen which 

 showed the reaction of laccase and other oxidases (oxi- 

 dizing enzymes) : it blued guaiacum, its action was pre- 

 vented by heat and acid, and it could be precipitated by 

 alcohol, and redissolved in water without losing its oxi- 

 dizing powers characteristic properties of all enzymes. 

 Wolf with his colloidal iron compounds, and Euler and 

 Bolin with their calcium salts of organic acids (citric, 

 malic, etc.), and many others, have produced strong evi^ 

 dence in favor of the view that many of the enzymes, at 

 least many of the so-called oxidases, are relatively simple 

 substances. 



Along somewhat modified lines is the work of Panzer, 



