A hydrolytic derivative of the globulin edestin and its relation to Weyl's albuminate and the histon group.

  • Thomas Burr Osborne
Date:
[1900]
Catalogue details

Licence: In copyright

Credit: A hydrolytic derivative of the globulin edestin and its relation to Weyl's albuminate and the histon group. 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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    described, than those of the endosperm of wheat and other seeds. (Cf. Martin, Jour, of Physiology, 8, viii, 1887.) Since this derivative of edestin is a definite substance, well characterized by its properties and reactions, I propose to call it edestan, and if, as seems probable, the other protein bodies yield similar derivatives, these may be named in a like manner by changing the termination in, usually applied to the protein substance, to an. The group of substances belonging to this class may be called proteans, thus following the practice whereby the more altered and basic hydrolytic protein deriva- tives are designated proteoses, and the individual members albumose, caseose and so forth. It is important that a distinction should be made between these proteans and those products which result from a more profound change in the protein molecule, caused by the action of stronger acids and alkalies, and which are now known as acid and alkali albumin. a. Action of ivater on edestin. Pure water, because it is but slightly ionized, has little effect on pure edestin* at the room temperature. If, however, car- bonic acid is present, edestan is formed in decidedly larger amount. Gram portions of pure and perfectly neutral edestin were suspended in water, agitated frequently and exposed to differ- ent temperatures for definite periods of time. An equal volume of 20 per cent, sodium chloride solution was then added to each, and the solution made neutral to phenolphthalein, by which the unaltered edestin was at once dissolved and the formation of edestan was stopped. The edestan was allowed to settle over night and was then easily collected on a filter and thoroughly washed with 10 per cent, sodium chloride brine, until the washings showed no trace of the xanthoproteic reaction. Nitrogen was determined in the residue and the amount of edestin calculated by multiplying the nitrogen by 5.4, * For the properties of edestin, and its relations to acids and alkalies, the paper following this should be consulted, in which will be found in detail the evidence on which are based many of the statements made in this paper, concerning edestin and its compounds. Also, Osborne, “ On some definite compounds of protein bodies,” Jour. Amer. Chem. Soc., 21, 486.
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