Proteins and Carbohydrates of the Cholera and Cholera-Like Vibrios. ∗

Abstract

The results of the van Slyke analyses of the proteins of the cholera and cholera-like vibrios, which we have published elsewhere, 1 may be briefly summarized. No differences in nitrogen distribution could be found between proteins of the agglutinating vibrios and of the non-agglutinating or water vibrios. In comparison with similar analyses of other bacteria, which have been reviewed by Hirsch, 2 the vibrios form a well-defined group with a relatively high content of the simpler amino acids (average, 55.7%) and a lower content of the basic amino-acids (average, 24.4%) than has previously been found in the bacteria. The figure for amide nitrogen, which averaged 6.8%, is about half that reported for other microorganisms. Taken altogether, the van Slyke analyses indicated that the vibrios had, relative to other bacteria, a comparatively simple structure, and as already stated the nitrogen distribution appeared identical in all of them from whatever source. An elementary analysis of the vibrio proteins was also made and in no case could any differences in these constituents be detected in the group. 3

We have also studied the vibrio proteins by the method of “race-mization” in dilute alkali, which was developed by Woodman 4 and based on the earlier work of Dakin. 5 Woodman's method consists of following the optical activity of the protein in dilute alkali and plotting the degree of specific rotation against time, and was applied by him to the study of the globulins and albumins of cow sera and colostrum. Since it appeared from our previous work that the vibrios were closely related in their protein constituents, it seemed that this method might be applied to a possible differentiation of them.