Purified Muscle Proteins and the Walking Rate of Ants.

librated with 0.02 AI KPO4, pH 8.0, containing 0.01 M 2-mercaptoethanol. Linear gradients were applied and the purifications obtained are expressed relative to the supernatant fluid of the sonic extract; all solutions contained 0.01 Al 2-mereaptoethanol. Glucosylating enzyme: gradient of 0.08 to 0.32 M NaCl in 0.02 M KPO4, pH 8.0-30X purification; dCTPase: gradient of 0.08 M to 0.32 Ml NaCl in 0.02 M KPO4, pH 8.0-24X purification, rechromatographed with a gradient of 0.06-0.32 M KPO4, pH 6.5-85X purification; dHMC-5-P kinase: gradient of 0.06 to 0.32 M KPO4, pH 6.5-20X purification; hydroxymethylating enzyme: gradient of 0.3 M KPO4, pH 6.5 to 1.0 M KPO4, pH 6.1-230X purification. Fractions containing 2-mercaptoethanol were not frozen. Active fractions were concentrated by precipitation with solid (NH4)2SO4. Further details of the purification procedures will be published elsewhere. 20 Glaser, L., and D. Brown, these PROCEEDINGS, 41, 253 (1955); Glaser, L., J. Biol. Chem., 232, 627 (1958). 21 Personal communication from Dr. M. J. Bessman. 22 We are indebted to Dr. R. L. Sinsheimer for the sample of OX174 DNA. 23 Personal communication from Dr. I. R. Lehman. 24 Chargaff, E., in Nucleic Acids, ed. E. Chargaff and J. N. Davidson (New York: Academic Press, Inc., 1955), 1, 307. 25 Dunn, D. B., and J. D. Smith, Nature, 174, 305 (1954); S. Zamenhof and G. Griboff, Nature, 174, 306 (1954). 26 Burton, K., Biochem. J., 61, 473 (1955). 27 Tomizawa, J., and S. Sunakawa, J. Gen. Physiol., 39, 553 (1956). 28 Hershey, A. D., and N. E. Melechen, Virology, 3, 207 (1957). 29 Watanabe, I., Biochim. et Biophys. Acta, 25, 665 (1957); Watanabe, I., and Y. Kiho, Proc. Int'l. Synmp. Enzyme Chemistry (Tokyo-Kyoto, 1958), p. 418; Hershey, A. D., A. Garen, D. K. Fraser, and J. D. Hudis, Carnegie Institution of Washington Year Book, 53, 210 (1953-1954). 30 Cohen, S. S., Abstracts of the American Chemical Society, Meeting, September, 1958, p. 22C. 31 Pardee, A. B., and R. E. Kunkee, J. Biol. Chem., 199, 9 (1952). Dr. Fred Bergmann has found no changes, following T2 infection of E. coli B, in amino acid "activation" levels for valine, isoleucine, methionine, leucine, phenylalanine, tryptophan, and tyrosine. We have observed that levels of the following activities did not change (4±20 per cent) within 15 min after E. coli B infection with phage T2: PRPP synthetase, orotate + PRPP conversion to uridylate, inorganic pyrophosphatase, adenine + PRPP conversion to adenylate, and adenylate kinase. 32 Hogness, D. S., M. Cohn, and J. Monod, Biochim. et Biophys. Acta, 16, 99 (1955); Rotman, B., and S. Spiegelman, J. Bacteriol., 68, 419 (1954).