SYNTHETIC PRODUCTION OF FAT 365 



ferments present with toxines. It has been especially sug- 

 gested, too, that enzymes, just as toxines, are perhaps com- 

 posed of two parts, one a thermostable ' ' amboceptor " and 

 the other a thermolabile * i complement. ' ' Observations like 

 those of H. Donath, of the possibility of partially reactivat- 

 ing pancreatic steapsin which had been inactivated by ex- 

 posure to a temperature of about 60 C. by a thermolabile 

 agent present in normal horse serum, invariably make it 

 seem very likely that the pancreatic steapsin is of a complex 

 nature. It should be added, too, that appearances of this 

 and similar nature fall in very well with the ideas of Victor 

 Henri, who, on the basis of ultramicroscopic observations, 

 has brought into the reach of possibility an explanation of 

 ' ' complement eif ects ' ' from purely physical factors. 40 



Synthetic Production of Fat by Reverse Ferment Action 

 of Lipase. The fermentative kinetics of pancreatic lipase 

 has been closely studied from a number of standpoints 41 ; but 

 it is impossible here to enter into the details of this phase of 

 the subject, which belong properly to the sphere of physical 

 chemistry. Reference may be made merely to one point, 

 because of its special physiological interest, that is, the 

 fact that the lipases concerned in digestion, coming from 

 the pancreatic and intestinal secretions, are not only 

 capable of separating fat into glycerol and fatty acids, but 

 also of bringing about in a reverse way a synthetic produc- 

 tion of fat from its components. We are concerned here 

 with a true reversible enzyme action, 



Gylcerol + Fatty acids < > Neutral fat, 



which, according to conditions, can take place in either 

 direction, and which brings somewhat closer to our under- 



40 V. Henri, Congress of Physiologists, Heidelberg, Aug., 1907, Cenfralbl. 

 f. Physiol., 21, 477, 1907. 



41 Kastle and IxJwenhart, H. Engel, J. Lewkowitsch and J. J. R. Macleod, 

 Taylor, A. Kanitz, Zeitechr. f. physiol. Chem., 46, 482, 1905; E. F. Terroine, 

 Biochem. Zeitschr., 23, 404, 1910, and others. Cf. therein the Literature. Cf. 

 also 0. Rosenheim and collaborators, Jour, of Physiol., 40, Proc. Physiol. Soc., 

 1910. 



