The basic character of the protein molecule and the reactions of edestin with definite quantities of acids and alkalies.

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

Licence: In copyright

Credit: The basic character of the protein molecule and the reactions of edestin with definite quantities of acids and alkalies. 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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    nature, for in the acid H0A1, (BOH)2 Si4O10 the nine hydro- gens may be replaced to a large extent by the trivalent metal aluminium or by the bivalent metals magnesium and iron with- out any decided change in crystalline form. This leads to the consideration of a certain phase of isomorphism which, as it seems to us, has not been considered with sufficient care, namely, the mass effect of complex radicals in influencing or controlling crystallization.” If such be the case with a mineral acid containing but (41 )„ atoms we certainly should expect the mass influence of a mole- cule containing approximately (2,000)n atoms to be all-con- trolling. IV. Reactions of Edestin with larger quantities of Acid. It has long been known that protein substances combine with acids, and it is a common practice to determine the amount of acid combined with products of gastric digestion. In these products, however, the combined acid is chiefly held by proteoses and peptones, bodies that are known to have more basic proper- ties than the native proteins from which they originate. (Cf. Conheim & Krieger, Zeit. f. Biologie n. F., 22, 95.) Pan- ormoff (Panormoff, Jour. d. russ. phys.-chem. Gesellsch., 31, 556) has recently described definite compounds of ovalbumin with different acids, but these contain a much larger proportion of acid than the salts of edestin just described, and are doubtless compounds of a different order (see preceding paper). I have, however, obtained evidence that edestin also enters into definite reaction with similar large quantities of acid. A study of the action of water and acids upon edestin has shown that a hydrolytic change is effected in the edestin mole- cule, whereby a more basic derivative is formed, which shows an entirely different behavior with alkalies and salt solutions from that exhibited by the original, unchanged edestin. It is probable, therefore, that these more acid compounds are not salts of edestin, but salts of more basic derivatives, which form intermediate steps in a series of changes leading to the so-called “acid albumin.” Whether or not these changes are common to the other “native proteids” I have not as yet ascertained with certainty, but it is probable that they are. Gram portions of