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THE ARGININE AND PREARGININE GROUPS IN EDESTIN

The author corroborates the data of Schmidt showing that the dissociation index of the third group of arginine is pK(3)' = 12.5. New titration data of edestin have been obtained in very alkaline solutions and show that there is a corresponding group with a titration index of pG' = 12.0, bu...

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Detalles Bibliográficos
Autor principal: Simms, Henry S.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1930
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2141091/
https://www.ncbi.nlm.nih.gov/pubmed/19872577
Descripción
Sumario:The author corroborates the data of Schmidt showing that the dissociation index of the third group of arginine is pK(3)' = 12.5. New titration data of edestin have been obtained in very alkaline solutions and show that there is a corresponding group with a titration index of pG' = 12.0, but present in much less quantity than can account for the arginine found on hydrolysis. The data support the theory that the combination of strong base or strong acid with proteins is produced by the formation of salts with the "extra groups" of those trivalent amino acids which can be isolated from the protein, with the exception of arginine. Arginine contributes to the titration curve in much smaller amount than is found on hydrolysis. This deficiency in the arginine group may be accounted for by the basic group in proteins having a titration index of pG' = 3.8 to 4.6 (depending on the protein), which apparently yields arginine on hydrolysis, and may properly be called prearginine.