286 F. CEDRANGOLO 



morrow*, but using very simple technique, under the action of one or two 

 factors similar or possibly identical to those which presumably have been able 

 to act in the primitive atmosphere and lithosphère. 



In conclusion we must transfer to the synthesis of one protid starting from the 

 amino acids an experimental model similar to that used by Miller for the syn- 

 thesis of amino acids starting from products which notoriously belong to the 

 field of inorganic chemistry [7, 8] ; 



(2) to demonstrate that the viruses are able to grow also outside of precon- 

 stituted living beings, which means in artificial organic medium in absence of 

 cells. At this point we recall that Olitsky [19] has claimed to have obtained the 

 reproduction of the virus of mosaic of tobacco and of tomatoes in one acellular 

 extract obtained from the leaves and roots of tomato plants. Successively 

 Mulvania [20] has demonstrated that it was an erroneous interpretation of the 

 results, which were the same if the experiments were performed using distilled 

 water instead of extracts. In reality, it seems to me that until now, not enough 

 importance was given to the fact that the organization of thousands of amino 

 acids and other simple components in one macromolecule is an endoergonic 

 process [8, 14]. The cultivation of virus on artificial acellular medium (in which 

 reactions with energy production do not take place) evidently cannot give 

 positive results. 



I refer at this time to a biochemical example : the synthesis of cocarboxylase 

 from aneurin and phosphates does not happen in the usual acellular extract, 

 but takes place only if we add to this extract a substance or a system able to 

 furnish enough energy. So I [21, 22] since 1942 was able to construct an acel- 

 lular model, which is able to synthesize the cocarboxylase from aneurin and 

 phosphates. This model was composed of 2 systems : (a) system aneurin + 

 phosphates -r phosphatase, (b) D-amino acid + D-amino acid oxidase. The 

 energy split off from system b (energy liberated from the deamination of the 

 unnatural amino acid) was utilized from system a for the synthesis of the cocar- 

 boxylase. We believe it is opportune to report here the technique and the ex- 

 perimental data obtained in this research [21, 22]. 



D-AMINO ACID OXIDASE 



Rat kidney (only cortical section) cut in little pieces and washed is crushed in 



an ice-chilled mortar with quartz sand. 20 ml of water are added for each g of 



* The actual studies of the molecular structure of proteins suggest the existence of 

 subunits which are always the same and are often repeated in the molecule. For example, 

 it is admitted that in insulin exists a subunit with molecular weight of 6000 which is 

 repeated 8 times in the molecule (6000 • 8 - 48,000 — molecular weight of insulin). 

 So far it is evident that the problem of the structure of one protid becomes a more simple 

 problem and also the synthesis in the laboratory of one protid from amino acids which 

 are forming it, seems to be a realizable aim in the near future. A recent editorial article 

 in the Nature, Land., in connection with the important studies of Sanger on 

 insulin, shows indeed '. . . the possibility that insulin itself may ultimately be completely 

 synthesized in the laboratory' [17]. From another point of view, considering the prac- 

 tically infinite variety of proteins theoretically possible [i, 2], it is to be expected also 

 that we can obtain very soon the synthesis of proteins which do not exist in nature. 

 The study of the properties and of the biological actions of these artificial products will 

 be stimulating [18]. 



