24. 



All proteins, (v;ith the oxc option of prct- 

 R-mines and histonos, ) hav::; apprcxitnat oly tho 

 following p3rc3ntag3 ccTnposition; 



Carbon Hydro g2n Nitrogen Oxygon Sulphur 

 50-55 6.9-7.3 15.0-19.0 19.0-24 0.3-2.4 



If WD takG, as a roprosentativ o sample of 

 our hypcthotical substance, a compl ot o tripla 

 junction of the gamrna-gamrna-gi^jTiTTia typo and cn3- 

 half of oach of th 3 thr^e adj ac 3nt spirals, th on 

 the orapirical formula th3r3for may b: dorivod 

 as follows: 



/co\ 



H3 

 This will give the following percentage composition: 



Carbon Hydrogen Nitrogen Oxygon 

 53.8 5,8 18.8 21.5 



The values thus calculated are in fairly 

 accurate agreement with the exporimental values, 

 except that the hydrogen is slightly low, but that 

 is just what would be expected because of the 

 difficulty of obtaining proteins in perfectly 

 anhydrous condition. Another possible explana- 

 tion for the low hydrogen percentage is that the 

 protein molecule in v/at er solution may consist ^f 

 only a thin sheet t^iken transversely of the ax 3S 

 of the spirals, so that many additional hydrogen 

 atoms or hydroxyl groups v/ill b^ requirod for 

 combination with the free ends of the spirals. 

 For exo.mpl e, if wo include only tw^ additional 

 hydrogen atoms in our th3cr?tical formula, the 

 porcantago of hydro g on will bo brought up to the 

 values obtained 3xp or im entail y. 



