ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Description / Table of Contents:
Es wurde festgestellt, daß das Pflanzenglobulin Legumin sich in salzhaltigem, heißem, 35-40% Propylalkohol löst. Diese Lösungen, wenn gekühlt, erstarren zu klaren Gallerten, falls die Konzentration des Legumins nicht zu klein ist; wenn gegossen auf Glas, liefern die Lösungen hartnäckig an der Glasoberfläche haftende, harte Filme. Viskositätsmessungen und Titrationen mit Jod zeigen, daß Legumin in heißen, salzhaltigen Propylalkohol-Wasser-Gemischen denaturiert ist. Flockungsversuche von Legumin aus Salzlösungen durch Propylalkohol und andere organische Lösungsmittel (bei Zimmertemperatur) zeigen, daß bei gewissen mittleren Konzentrationen der organischen Stoffe die Gemische von Wasser-Salz-Org.Stoff stark peptisierend, d. h. lösend wirken. Die Viskosität des Legumins in gemischten Lösungsmitteln ist höher als in Salzlösungen und erhöht sich mit der Zeit, falls die Konzentration des Legumins über 0,1% ist.
Notes:
Legumin was obtained from horse beans, green peas and vetches, and the solubility and gelation of this protein in some mixed solvents was observed. The following results were obtained: 1Legumin dissolves at 75-85° in 35-40 vol-% n-propyl alcohol containing 0.2-1,0 Mol/l such neutral salts as NaBr, KI, magnesium chloride etc. If the concentration of legumin is high enough (2-4%) the solutions set upon cooling and become clear, stable jellies. Those of the jellies which are loose are thixotropic. If poured onto glass, legumin renders tough films which adhere strongly to the surface.2If propyl alcohol is added to legumin which is dissolved in a salt solution, precipitation takes place at 5-25 vol-% and at over 50 vol-% propyl alcohol, but in the limits of 30-45 vol-% the mixtures are clear and stable.3The viscosity numbers of legumin in the solutions containing about 40 vol-% propyl alcohol are much higher than in pure salt solutions, and the viscosity increases in time, if the concentration of legumin is over 0,1%. The heated solutions have a greater viscosity than the unheated.4The titrations with iodine showed that the amount of reducing groups (HS-) do not increase under the influence of propyl alcohol at low temperatures, but such an increase takes place upon heating the mixtures up to 75-85° for 30-60 minutes.5Dioxane, pyridine and acetic acid act like propyl alcohol except that the concentration limits in which precipitation and solubilisation occur are somewhat different. 50% ethyl alcohol or acetone have a much weaker solubilizing power than propyl alcohol or dioxane.6The solubility in cold mixed solvents is due to the interaction of legumin with the solvent. This interaction is very little dependent on pH or some chemical changes of the protein. It is assumed that a moderate unfolding of the round shaped molecules of legumin occurs only upon heating the mixtures.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1950.020050204
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