ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The densities and water contents of large β-lactoglobulin crystals were determined as a function of relative humidity. When the specific volumes of the crystals (1/density) were plotted against their water contents, a straight line was obtained between 14 and 46% water. The extrapolation of this line by the graphical intercept method of Lewis and Randall gave a value of 0.772 for the specific volume of the protein and 0.983 for the specific volume of the water in the β-lactoglobulin crystal. Subtracting the specific volume of the protein in the crystal from the specific volume of the anhydrous protein (0.802-0.772) gave a value of 0.030 ml. for the contraction of one gram protein on becoming hydrated.A value of 0.021 ml. was calculated for the contraction of water per gram protein by the difference between the apparent specific volume of the protein in solution, assuming water to have a specific volume of 1.003, and the value of 0.772 for the specific volume of the protein in the crystal. There was good correlation between the value for contraction of water as calculated from the ionic groups of the protein and the observed contraction value.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1954.120120125
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