Nucleosidediphosphatase activity in the Golgi apparatus and its usefulness for cytological studies.

the solid state; 1711 cm-' in chloroform) is caused mainly by a C = 0 vibration. 30 Miles, H. T., unpublished experiments. 31 Davies, D. R., Nature, 186, 1030 (1960). Dr. Davies has informed the author that in his opinion the Watson-Crick arrangement (XIII) is more likely for steric reasons but that the X-ray data could not exclude XIV (R' = H) without a great deal of additional work. 32 Watson, J. D., and F. H. C. Crick, Nature, 171, 737 (1953). 33 Pauling, L., and R. B. Corey, Arch. Biochem. Biophys., 65, 179 (1956). 34 Felsenfeld, G., D. R. Davies, and A. Rich, J. Am. Chem. Soc., 79, 2023 (1957). 3 A variety of hydrogen bonding schemes had been discussed by Donohue, these PROCEEDINGS, 42, 60 (1956), but there was no evidence indicating that the suggested structures occurred in nature. 36 An examination of scale models can readily demonstrate that no other bonding scheme permits both the glycosidic bonds of the G-C pair to be simultaneously superimposed on those of the AT pair of structure XII. The author wishes to thank Dr. D. R. Davies for helpful discussions of some of the crystallographic considerations involved. 37 armur, J., and P. Doty, Nature, 183, 1427 (1959). 38 Chargaff, E., in The Nucleic Acids (New York: Academic Press, 1955), vol. 1, p. 348. 39 Wilkins, M. H. F., A. R. Stokes, and H. R. Wilson, Nature, 171, 738 (1953). 40 Franklin, R. E., and R. G. Gosling, Nature, 171, 740 (1953). 41 Langridge, R., H. R. Wilson, C. W. Hooper, M. H. F. Wilkins, and L. D. Hamilton, J. Molec. Biol., 2, 19 (1960). 42Langridge, R., D. A. Marvin, W. E. Seeds, H. R. Wilson, C. W. Hooper, M. H. F. Wilkins, and L. D. Hamilton, J. Molec. Biol., 2, 38 (1960). 43 Bredereck, H., and A. Martini, Chem. Ber., 80, 401 (1947).