ANTI-ENZYME IMMUNITY 223 



sera capable of inhibiting amylase activity, Liiers and Albrecht found 

 perfect agreement in their results and any doubt in regard to the 

 existence of anti-enzyme antibody was removed. 



3. Invertase and Its Properties 



Five highly purified invertase preparations were obtained by Adams 

 and Hudson (1943). All behaved as ampholytes, precipitating either 

 with base precipitants (picric and flavianic acids, Reinecke salt, am- 

 monium rhodanilate and picrolonic acid) or acid precipitants (cupric, 

 or uranyl acetate). They consisted chiefly of protein although they still 

 contained a small amount of carbohydrate. The relative activities of 

 these preparations, at pH conditions optimal for each substrate, were 

 found (Adams, Richtmyer and Hudson, 1943) to be in the order of 



sucrose > rafifinose > stachyose ]> inulin 



Their findings agreed with the observation of Weidenhagen that 

 one enzyme, /8-fructofuranosidase (/8-h-fructosidase by Weidenhagen) 

 is responsible for the hydrolysis of the simple /8-fructofuranosides such 

 as sucrose and raffinose (pH 5.0-5.5), and stachyose (pH 5.1), a 

 tetrasaccharide. They disagree with him in that inulase is another 

 enzyme. They consider the question open whether the linkages in 

 inulin are a- or jS-. 



Despite the high concentration of i8-fructofuranosidase in their 

 invertase preparations no appreciable hydrolysis of melezitose (3-a-D- 

 glucopyranosido-/3-D-fructofuranosido-a-D-glucopyranoside, or sucrose 

 with an additional glucose molecule as a substituent group on the third 

 carbon atom of the fructose moiety) was observed at a pH of 4.0, 5.3 

 or 7.0. As little as 1.5 per cent hydrolysis was detected with a large 

 sample of enzyme. The inability of invertase to hydrolyze melezitose 

 was attributed to the presence of the glucosido substituent on the third 

 carbon atom of the fructofuranose moiety. 



In agreement with Weidenhagen's theory, Adams et al. found that 

 Baker's A enzyme preparation was inactive toward melibiose (6-a-D- 

 galactopyranosido-D-glucose), the a-phenyl-a-methyl-D-galactosides and 

 /?-methyl-L-arabinoside (at pH 4.0, 5.3 and 7.0). The presence of 

 melibiase (a-D-galactosidase) had never been reported in top yeast, so 

 the observed inactivity was not unexpected. They found that brewer's 

 yeast enzyme preparations containing a-D-galactosidase, in agreement 



