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

  • Osborne, Thomas B. (Thomas Burr), 1859-1929.
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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    seem that edestan and globin have little in common, since the two former yield little or no proteoses on pepsin digestion, whereas edestin yields such abundantly and globin doubtless does the same. From the facts now at our command it is evident that we have two different classes of bodies which conform pretty closely to the reactions characteristic of the histons. It is important to recognize this fact, since otherwise confusion will result if these two classes are not distinguished from one another, and protein derivatives produced by the acid used in preparing these substances may be regarded as actual constitu- ents of the tissues. Summary. By the action of water or very dilute solutions of acids, the globulin edestin is converted into a substance insoluble in saline solutions of moderate concentration. This derivative of edestin is formed by hydrolysis, the amount formed being proportional to time and the concentration of the solution in hydrogen ions. In pure water less is formed in a given time than in water containing carbonic acid. More is formed by a given quantity of hydrochloric acid than by an equivalent quantity of phosphoric acid, and by either of these acids much more is formed than by an equivalent of acetic acid. This substance is the same as that designated as “albuminate” *by Weyl, which is formed in greater or less amount in prepara- tions of crystallized edestin made in the usual manner, and is without doubt the first product of the hydrolytic changes leading to the formation of the so-called acid albumin. It is probable that the products insoluble in saline solutions which are formed from other globulins, originate from the same cause, and that these form a distinct class of hydrolytic derivatives of the native protein molecules. For this derivative of edestin the name edestan is proposed. The ultimate composition of edestan is the same, so far as can be determined by analysis, as that of edestin from which it originates. Edestan forms salts with hydrochloric acid which react acid toward phenolphthalein to the full extent of the combined acid. One salt, having an acidity equivalent to 20.0 cc. of a cen-