A GENERAL METHOD FOR THE LABELING OF THE ACTIVE SITE OF ANTIBODIES AND ENZYMES

1 Ames, B. N., J. Biol. Chem., 228, 131 (1957). 12 Ames, B. N., and B. L. Horecker, J. Biol. Chem., 220, 113 (1956). 13 Ames, B. N., J. Biol. Chem., 226, 583 (1957). 4 Adams, E., J. Biol. Chem., 209, 829 (1954); 217, 325 (1955). 1" Worthington Biochemical Corp., Freehold, New Jersey. The protein concentration of this diaphorase solution is approximately 5 mg/ml. 1New Brunswick Scientific Co., New Brunswick, New Jersey. 17 Fischer, E., and L. H. Cone, Annalen, 363, 116 (1908). We are indebted to Dr. Howard Bond who synthesized some of the formylhistidine used in this study. 18 In the dialysis of the extracts in some of the later experiments tris-(hydroxyamino)methane buffer, 0.01 M, pH 7.5, was substituted for the triethanolamine buffer, 0.01 M, pH 7.5, described previously4 as this buffer did not require a correction in the protein determinations. 19 Peterson, E. A., and H. A. Sober, J. Am. Chem. Soc., 78, 751 (1956). 20 This experiment was done in collaboration with Dr. Dean Cowie to whom we are indebted for permission to present these data and for helpful discussions. 21 Cowie, D. B., G. N. Cohen, E. T. Bolton, and H. de Robichon-Szulmajster, Biochim. et Biophys. Acta, 34, 39 (1959). 22Lowry, 0. H., N. J. Rosenbrough, A. L. Farr, and R. J. Randall, J. Biol. Chem., 193, 265 (1953). 23 It has been called to our attention that a similar hypothesis has been suggested by Dr. F. Jacob, Harvey Lecture (1959), in press. 24 Haas, F., M. B. Mitchell, B. N. Ames, and H. K. Mitchell, Genetics, 37, 217 (1952). 25 Leupold, U., Cold Spring Harbor Symposium Quant. Biol., 23, 161 (1958). 26Ames, B. N., unpublished observations. 27 Schwartz, J. H., W. K. Maas, and E. J. Simon, Biochem. et Biophys. Acta. 32, 582 (1959). 2 Adelberg, E. A., and H. E. Umbarger, J. Biol. Chem., 205, 475 (1953). 29 Brooke, M. S., D. Ushiba, and B. Magasanik, J. Bact., 68, 534 (1954). 30 Yates, R. A., and A. B. Pardee, J. Biol. Chem., 221, 757 (1956). 31 Strecher, H. J., J. Biol. Chem., 225, 825 (1957). 32 Wormser, E. H., and A. B. Pardee, Arch. Biochem. Biophys., 78, 416 (1958). 33 Umbarger, H. E., and B. Brown, J. Biol. Chem., 233, 415 (1958). 34 Wyngaarden, J. B., and D. M. Ashton, Nature, 183, 747 (1959). 31 Moyed, H. S., and M. Friedman, Science, 129, 968 (1959).