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THE ULTIMATE UNITS IN PROTEIN SOLUTIONS AND THE CHANGES WHICH ACCOMPANY THE PROCESS OF SOLUTION OF PROTEINS

1. The experiments show that suspensions of finely divided particles of insoluble proteins incapable of swelling in acid (denatured egg albumin, casein trichloroacetate, sulfate, etc.) raise the viscosity of the suspension but little and that the influence of acid on the viscosity is negligible. 2....

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Detalles Bibliográficos
Autores principales: Loeb, Jacques, Kunitz, M.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1924
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2140643/
https://www.ncbi.nlm.nih.gov/pubmed/19872089
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author Loeb, Jacques
Kunitz, M.
author_facet Loeb, Jacques
Kunitz, M.
author_sort Loeb, Jacques
collection PubMed
description 1. The experiments show that suspensions of finely divided particles of insoluble proteins incapable of swelling in acid (denatured egg albumin, casein trichloroacetate, sulfate, etc.) raise the viscosity of the suspension but little and that the influence of acid on the viscosity is negligible. 2. The same is true for solutions of certain genuine proteins such as genuine crystalline egg albumin. 3. In contrast with these are proteins which swell in acid. It can be shown that where acid swelling of particles occurs, the viscosity is of a higher order of magnitude than where the swelling of particles is impossible and that the influence of acid on viscosity runs in these cases parallel to the influence of acid on swelling. This is shown to be the case for casein in HCl. 4. It is shown that the swelling of the powdered particles which determines the high order of viscosity varies according to the theory of membrane equilibria. 5. These results are used to ascertain with the aid of viscosity measurements whether the ultimate units of genuine protein in solutions are aggregates large enough to give rise to a Donnan equilibrium; or whether they consist of particles below this limit; and in what porportion the two kinds of units are contained in the solution. 6. It is found on the basis of viscosity measurements that when 1 gm. of isoelectric casein is dissolved in HCl so that the solution has a pH of 2.45, more than one-half of 1 gm. of casein must exist as units too small to give rise to a Donnan equilibrium, while the rest must exist in units still capable of undergoing swelling in acid.
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spelling pubmed-21406432008-04-23 THE ULTIMATE UNITS IN PROTEIN SOLUTIONS AND THE CHANGES WHICH ACCOMPANY THE PROCESS OF SOLUTION OF PROTEINS Loeb, Jacques Kunitz, M. J Gen Physiol Article 1. The experiments show that suspensions of finely divided particles of insoluble proteins incapable of swelling in acid (denatured egg albumin, casein trichloroacetate, sulfate, etc.) raise the viscosity of the suspension but little and that the influence of acid on the viscosity is negligible. 2. The same is true for solutions of certain genuine proteins such as genuine crystalline egg albumin. 3. In contrast with these are proteins which swell in acid. It can be shown that where acid swelling of particles occurs, the viscosity is of a higher order of magnitude than where the swelling of particles is impossible and that the influence of acid on viscosity runs in these cases parallel to the influence of acid on swelling. This is shown to be the case for casein in HCl. 4. It is shown that the swelling of the powdered particles which determines the high order of viscosity varies according to the theory of membrane equilibria. 5. These results are used to ascertain with the aid of viscosity measurements whether the ultimate units of genuine protein in solutions are aggregates large enough to give rise to a Donnan equilibrium; or whether they consist of particles below this limit; and in what porportion the two kinds of units are contained in the solution. 6. It is found on the basis of viscosity measurements that when 1 gm. of isoelectric casein is dissolved in HCl so that the solution has a pH of 2.45, more than one-half of 1 gm. of casein must exist as units too small to give rise to a Donnan equilibrium, while the rest must exist in units still capable of undergoing swelling in acid. The Rockefeller University Press 1924-03-20 /pmc/articles/PMC2140643/ /pubmed/19872089 Text en Copyright © Copyright, 1924, by The Rockefeller Institute for Medical Research This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Article
Loeb, Jacques
Kunitz, M.
THE ULTIMATE UNITS IN PROTEIN SOLUTIONS AND THE CHANGES WHICH ACCOMPANY THE PROCESS OF SOLUTION OF PROTEINS
title THE ULTIMATE UNITS IN PROTEIN SOLUTIONS AND THE CHANGES WHICH ACCOMPANY THE PROCESS OF SOLUTION OF PROTEINS
title_full THE ULTIMATE UNITS IN PROTEIN SOLUTIONS AND THE CHANGES WHICH ACCOMPANY THE PROCESS OF SOLUTION OF PROTEINS
title_fullStr THE ULTIMATE UNITS IN PROTEIN SOLUTIONS AND THE CHANGES WHICH ACCOMPANY THE PROCESS OF SOLUTION OF PROTEINS
title_full_unstemmed THE ULTIMATE UNITS IN PROTEIN SOLUTIONS AND THE CHANGES WHICH ACCOMPANY THE PROCESS OF SOLUTION OF PROTEINS
title_short THE ULTIMATE UNITS IN PROTEIN SOLUTIONS AND THE CHANGES WHICH ACCOMPANY THE PROCESS OF SOLUTION OF PROTEINS
title_sort ultimate units in protein solutions and the changes which accompany the process of solution of proteins
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2140643/
https://www.ncbi.nlm.nih.gov/pubmed/19872089
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