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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    lupin gives products differing little in composition though the more soluble contain somewhat less carbon and nitrogen and a very little more sulphur. In the less soluble fractions, which have otherwise nearly the same composition and properties, somewhat different amounts of sulphur were found; thus, four fractions contained, 37, 0.32; 39, 0.24; 42, 0.38, and 44, 0.33 per cent. Although these differences are slight they were shown to be actual by recently repeated determinations, using large quantities of substance. The average composition of the least soluble fractions from the blue and yellow lupin is very nearly the same with the exception of sulphur, about 0.2 per cent, more of which is found in the latter. The preparations obtained from these two seeds appear to be either compounds of one and the same protein body, conglutin, with more or less of some substance rich in sulphur, which is present in greater amount in the yellow than in the blue lupin, or mixtures of various proportions of similar proteins which con- tain very different amounts of sulphur. This latter supposition appears the more probable because about the same proportion of loosely-bound sulphur was found in all the preparations, whether they contained 0.30 per cent, or 1.4 per cent, of total sulphur. It is improbable that a sulphur-containing substance is combined with the protein from which the same proportion of lead sulphide can be obtained as from the protein itself. The total sulphur in the different preparations of conglutin used in the following experiments was: Table XVIII.—Percentage of Total Sulphur in Different Frac- tional Precipitates of Conglutin. Blue Lupin. Yellow Lupin. I 0-393 II 0-359 III 0.530 IV 0.954 V 1.378 Table XIX.—Percentage of Loosely-Bound Sulphur in the above Preparations. One gram boiled with 30 p. c. NaOH, Z11 and Pb(C2H8Oa)3. 7 1-2 hours. Preparation One gram, with 30 p. c. NaOH and Pb(CaHsOa)a at 165°. 5 1-2 hours. Preparation Preparation Preparation Preparation 0.372