LIFE S FRINGES 



by Janssen; these are, moreover, in striking agreement with what has 

 lately been learned concerning the structure of proteins. I may, how- 

 ever, present a bird's eye view of a single one of the hundreds of 

 schemes constructed, in which I must call particular attention to the 

 concept concerning the synthesis of the simplest nucleoprotein ; the prin- 

 ciple can be extended at will to the more complex members of the group. 



Eminent scientists have recently introduced the derogatory term 

 'paper chemistry' to indicate attempts such as Janssen's. I, too, fully 

 realize the conjectural nature of these ideas based on deduction; but 

 I feel compelled to stress two points in this connexion. Firstly, Jans- 

 sen's working hypothesis covers a phase of biochemistry that at present 

 can best be characterized as a vacuum. Secondly, it is tempting to coin, 

 as a counterpart for 'paper chemistry', the term 'paper physics', and 

 this immediately suggests accomplishments of leading scientists which, 

 in my opinion, clearly emphasize the right of biochemists, too, to for- 

 mulate, prior to their experimental work, hypotheses that can serve 

 as guides for their investigations. 



This may suffice; in the framework of the virus problem it is enough 

 to realize that out of the mist that surrounds us a vague possibility 

 emerges to the effect that some day a well-founded concept will devel- 

 op concerning the synthesis by a living cell of a nucleoprotein from 

 non-specific building blocks for which a nucleoprotein constituent of 

 the cell is directly responsible, so that the nature of the newly formed 

 molecule will be determined by the configuration of its progenitor, 

 and may even be identical with it. 



Now this viewpoint assumes a most suggestive aspect if it be con- 

 sidered in relation to the recent experimental results of another phase 

 of biochemistry, viz., the respiratory mechanism, which is gradually 

 being elucidated. The masterly investigations of Warburg and collab- 

 orators have, in fact, unequivocally proved that the simple dehydro- 

 genation of an oxidizable substrate by a yeast cell is also mediated by 

 a nucleoprotein. This primary agent is formed as a loose compound if 

 a specific protein is brought in contact with a nucleotide whose chem- 

 ical composition as nicotinamide-adenine-ribose-phosphate has mean- 

 while been elucidated almost completely. Remembering Stanley's 

 crystalline viruses, is it not extremely remarkable that quite recently 

 Negelein has reported that he has isolated also the protein carrier of 

 the substrate dehydrogenase in a crystalline form by precipitation 



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