6 4 



THE FORMATION OF PROTEIDS IN PLANT-CELLS. 



be any other one than form-aldehyde. If the fungi utilise once 

 leucin, another time tyrosin, a third time tartrate of ammonia, 

 then an oxidation must set. in to reach the common starting 

 point. l) And this must hold good also for the higher plants, for 

 it can hardly be assumed that the mode of protein formation is 

 here entirely different. If for the purposes of transportation and 

 transformation (conglutin into active albumin and living pro- 

 toplasm), in lupin-shoots, the reserve protein is first dissolved, 

 and split into a series of amido-products (leucin, admido-valeri- 

 anic acid, tyrosin, phenyl amido-propionic acid, arginin, etc.) by 

 an enzyme, then in all probability and logically all those different 

 products must be transformed into the common starting group: 

 formic aldehyde, and their nitrogen be liberated as ammonia; 

 thus the decomposition of leucin by oxidation might be expressed 

 by the following equation : 



C 6 H I3 NO, + 70 = 2C0 3 + H 2 0+4CHaO-LNH 3 . 



Form-aldehyde and ammonia, however, act noxiously and do 

 not remain as such for a second ; aspartic aldehyde being formed. 2) 

 This product however does neither remain unchanged, it will yield 

 either directly active albumen when all conditions are fulfilled, or 

 it will be stored up as asparagin if not all conditions are united 

 for protein production. 3) 



The asparagin in plants has two sources ; it may either be 

 formed directly from glucose, ammonia (or nitrates) and sulfates, 

 or it may be a transitory product between protein-decomposition 

 and reconstruction from the fragments. In both cases the im- 

 mediate processes connected with the formation of asparagin have 

 the greatest resemblance or are even identical, — although the 

 original materials are far different. 



1) Compare Chapt. Ill and Chapt. VIII of this essay. I developed the outlines 

 of this hypothesis first in Pujlg. Arch. 1880. 



2) The still hypothetical formation of aspartic aldehyde, from formic aldehyde 

 and ammonia may be expressed by 4CH20 + NH3 = C 4 H 7 N02+2H20 



3) Closely related to asparagin is succinic acid, found not only often in the 

 higher plants, but also encountered in fungi. I found this acid also in algae 

 (Spirogyra), in hay of meadows, in the cambial sap of conifers and in the common 

 yeast (Ber. Bayr. Akad. d. Wiss. 1878 ; Journ. f. prakt. Chem. 36). I observed 

 also this acid as a product of oxidation of albumen by potassium permanganate 

 (Journ. prakt. Chem. 31, 152). 



