Inborn errors of metabolism / by Archibald E. Garrod.

  • Garrod, Archibald E. (Archibald Edward), Sir, 1857-1936.
Date:
1909
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Inborn errors of metabolism / by Archibald E. Garrod. Source: Wellcome Collection.

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    well recognized, as also are the differences of their bile acids, to quote only a few of the most conspicuous examples. As instances of distinctive end-products of metabolism may be mentioned kynurenic acid, which is present in the urine of animals of the canine tribe and bears witness to a generic pecu liarity in the manner of dealing with the trypto phane fraction of proteins, and the excretion by birds and reptiles of the bulk of their nitrogenous waste in the form of uric acid, whereas in the urine of mammals urea is the chief nitrogenous constituent. A more extended study, even by strictly chemical methods, will doubtless serve to reveal innumerable minor differences, such as are foreshadowed by Przibram's 1 work on muscle proteins. The delicate ultra-chemical methods which the researches of recent years have brought to light, such as the precipitin test, reveal differences still more subtle, and teach the lesson that the members of each individual species are built up of their own specific proteins, which resemble each other the more closely the more nearly the species are allied. Obviously it is among the highly complex proteins that such specific differences are to be looked for, rather than in the simple end-products of their disintegration. The many amino-acids which enter into the structure of the protein molecules are capable of almost innumerable groupings and pro portional representations, and each fresh grouping will produce a distinct protein ; but all alike, in 1 Hofmeister's Beiträge zur ehem. Physiol, u. Pathologie, X9Ò2, Band ii, p. 143,