Dec., 1943
COMMUNICATION TO THE EDITOR CH~-C-N/
11
I
CH2 \CH%
I
H-yS/c\N/Zr
In a 500-cc. flask, 22.4 g. (0.2mole) of 2-amino-4-methylthiazole,’ 40.4 g. (0.2 mole) of trimethylene dibromide (Dow), and 60 cc. of absolute ethanol were mixed and the resultant solution was refluxed for four and one-half hours
2473
during which time hydrogen bromide was evolved. Upon cooling, 52.5 g. of white crystals melting at 160-191 O precipitated. Three recrystallizations-frommethanol yielded the hydrobromide melting at 235.5237’ (uncor.). The free base was found to be an oil and did not form a picrate. Anal. Calcd. for CrH11.NtBrS: N, 11.9; ionizable Br, 34.0. Found: N, 11.9; ionizable Br (by Volhard), 33.9. FRANKC. WHITMORE OF CHE.MISTRY ~ T ANTONW.~RYTINA RECEIVED SEPTEMBER 3, 1943
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(1) Bayers and Dickey. Org. S y n . , 19, 10 (1939).
C O M M U N I C A T I O N T O T H E EDITOR CONVERSION OF GLOBULAR TO ORIENTED FIBROUS PROTEINS. I. BY HEAT AND MECHANICAL WORKING Sir :
Indices
001
TABLE1
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Observed spacin and intensity, A,--Lactoglobulin Ovafburnin &Keratin
9.7
s
9.8
S
9.7
s
By a simple process we have converted a num200 4.68 S+ 4.65 S+ 4 . 6 5 VS ber of globular proteins to the fibrous form 111 4.7 M 4.7 M 4.7 M characterized by the diffraction pattern of 8210 3.72 M 3.75 M 3.75 s keratin. In its essence the process involves heat410 ... 2 . 2 w2.2 w ing the protein with water, followed by mechanical 020 3.26 M 3.33 M 3.33 s treatment, such as stretching in cold or hot water 220 2.71 W 2.75 W 2.7 W or water vapor, to extend and orient the peptide 030 2.16 w 2.18 w 2.2 w chains. Among the proteins which have thus 230 2.03 w + 2.03 w + 2.0 w given @-keratin patterns are casein, P-lactoglobulin, hemoglobin, ovalbumin, edestin, zein, ride or detergents. From a stretched film of heatand peanut and soybean proteins. A high degree denatured egg white, however, Astbury, Dickinof double orientation has been achieved in an son, and Baileya obtained a different pattern, the 4.7 A. (backbone) spacing occurring on the ovalbumin preparation. In the initial heating of protein and water, meridian and the 9.7 A. (side chain) spacing on partial crystallization of the protein occurs as the equator, while for @-keratinboth occur on the evidenced by the change in the diffraction pattern, equator. We have obtained this egg-white patM u s e rings becoming sharp and the number of tern from such proteins as casein, peanut protein, rings increasing. At the same time solubility hemoglobin, zein, edestin, and ovalbumin. Our decreases and tenacity increases. After heating, expenence with these proteins has shown that the application of high shear stress by extrusion or structure giving the egg-white pattern can be stretching produces ultimately the parallelism of converted into the &keratin structure by further extended peptide chains which gives rise to the mechanical working. Our results demonstrate that the conversion of @-keratinpattern.’ The best patterns have been obtained from globular to oriented fibrous proteins may be exP-lactoglobulin and ovalbumin. Data on these pected to be generally practicable. Tensile proteins are summarized in Table I, together with measurements have shown that the strength of indices and corresponding data on @-keratin of casein, lactoglobulin, and ovalbumin filaments is greatly increased by conversion of the protein to stretched wool and hair quoted by ClarkU2 With the exception of the natural fibrous the oriented fibrous form, It seems reasonable proteins, &keratin patterns have been obtained that an extension of this work may lead to signifipreviously only from edestin3 and ovalbumin14~5cantly improved protein plastics, films, and using denaturing reagents such as calcium d o - adhesives. (1) Addition of other reagents, for example ethanol, to some proteins obviates the necessity of heating. (2) G. L. Clark, “Applied X-Rays,” 3d ed., McGraw-Hill Book Co., New York, N . Y., lY40, p. ti48. (3) Astbury, Dickinson, and Bailey, Biochem. J . , 99, 2351 (1935). (4) Lundgren and O’Connell, I n d . Ens. Chcm., in press. ( 5 ) Palmer and Calvin. ‘1‘1115 TUUHNAI,, 66, 2187 (1943).
EASTERN REGIONAL RESEARCH FREDERIC R. SENTI LABORATORY C. ROLAND EDDY C. NUTTING PHILADELPHIA, PENNSYLVANIA GEORGE AGRICULTURAL RESEARCH ADMINISTRATION BUREAUOF AGRICULTURAL AND INDUSTRIAL CHEMISTRY DEPARTWENT OF AGRICULTURE UNITEDSTATES RECEIVED NOVEMBER 19, 1943
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