Sulphur in protein bodies.

  • Osborne, Thomas B. (Thomas Burr), 1859-1929.
Date:
[1900]
Catalogue details

Licence: In copyright

Credit: Sulphur in protein bodies. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    SULPHUR IN PROTEIN BODIES. By Thomas B. Osborne. I. Historical. Kruger (Kruger, Pfliiger’s Archiv. 43, 244) has pointed out that the “sulphur content of legumin, casein, fibrin and oval- bumin are to each other as 4: 8: 12: 16, from which one can conclude that the number of sulphur atoms in them are as i„ : 2n : 3,,” . . . “Leaving out of consideration the unknown molecular weight and, instead, taking into account the number of sulphur atoms, an equally great molecular weight may be assumed for all proteins. A comparison of this equally great atomic complex is possible, in respect to sulphur, because the proportion of the other elements in these bodies varies so little that it has no influence on the sulphur content.” Sometime ago, before I was aware of Kruger’s suggestion, I reached the same conclusion by a different line of reasoning. I pointed out (Jour. Amer. Chem. Soc. 21, 486) that the molecular weight of those proteins which contain but 0.4 per cent, of sulphur must be at least 15,000 if there are two atoms of sulphur in their molecules and that similar molecular weights are obtained for a large number of the more carefully analyzed proteins, if their simplest empirical formulas, calculated on the basis of a single atom of sulphur, are multiplied by such a whole number as to give molecular weights nearest to 15,000. The results thus obtained all fall so near to one another as to strongly suggest that all these bodies have similar molecular weights not far from (15,000),,. 1 he fact that the proteins all react with very small quantities of acids and alkalies and closely resemble one another in many of their physical characters, also indicates that they have similar high molecular weights. Further, the oxyhaemoglobins from horse and dog blood must contain at least one molecule of pro- tein, and as these have been shown by Zinoffsky (Zeit. f. physiol. Chem. 10, 16) and Jaquet (Ibid. 12, 284 and 14, 289) to contain respectively two and three atoms of sulphur to one of iron (see page 4^5)> the protein contained in them cannot have a molecu-