A crystalline bean seed protein in combination with phytic acid.

A protein combined with phytic acid has been extracted from the dried seeds of Phaseolus vulgaris, variety Great Northern, by the following method. &traction-l00 gm. of bean flour were stirred wit,h 100 ml. of N NaCl, followed by 800 ml. of water. The suspension was centrifuged and the sediment discarded. The pH of the turbid supernatant solution was lowered to 4.6 with about 7.0 ml. of N HCl, which produced a precipitate. The suspension was heated to 50” and the precipitate was removed by centrifugation. The pH of the supernatant fluid was lowered to 4.2 with about 4.0 ml. of N HCl, followed by 1 volume of water. The precipitate formed was collected by centrifugation and dissolved in 40 ml. of N NaCl, and the solution clarified by filtration in a Biichner funnel, through coarse paper covered with Filter-Cel, with the help of moderate suction (to avoid frothing and clogging). To the filtrate were added 400 ml. of water and the precipitate thus produced was collected by centrifugation. Crystallization at pH .&O-The precipitate was dissolved in 200 ml. of a buffer solution made from 3 volumes of N NaCl, 1 volume of N sodium acetate, 3 volumes of N acetic acid, and 1 of water. The solution was warmed t,o 50”, about 120 ml. of warm methanol were slowly added to it, and the container was placed in a bucket filled with water at 50” and allowed to cool slowly at room temperature. After 12 to 24 hours, the material crystallized in the form of elongated dodecahedra with slightly rounded edges (Fig. 1, left). These crystals were strongly anisotropic. Recrystallization was carried out several times by the same method. The material was finally dialyzed against distilled water and dried from the frozen state. The yield was 4 gm. Crystallization at pH 5.3-l gm. of the above powder was dissolved in 200 ml. of 0.5 N NaCl, the pH was adjusted to 5.3, and 100 ml. of methanol were added. The amorphous precipitate thus produced changed in a few hours at room temperature into rather coarsely shaped bisphenoids (Fig. 1, right), which were not birefringenh. Microscopic quadrangular bipyramids of sharp outline formed when the amorphous precipitate was allowed to stand under a cover-slip. These two crystalline forms and the absence