PORCINE CALCITONIN SIMPLE PROCEDURE FOR ISOLATION IN HIGH YIELD

A procedure for the isolation of calcitonin from porcine thyroid glands which offers the advantages of simplicity, economy, and high yield (40-60%) is presented. It involves three major steps: (1) extraction of calcitonin from dried defatted glands with 1-butanolacetic acid-water (12:3:5), followed by batchwise adsorption of contaminants with silicic acid and then trichloroacetic acid precipitation of biologic activity, (2) gel filtration of the trichloroacetic add precipitate on Bio-Gel P-6, and (3) gel filtration on Bio-Gel P-2. The final product has a biopotency and an amino acid composition essentially identical with those previously reported for porcine caldtonin (Beesley, T. E., Harman, R. E., Jacob, T. A., Homnick, C. F., Bitali, R. A., Veber, D. F., Wolf, F. J., Hirschman, R., and Denkewalter, R. G. (1968), J. Am. Chem. Soc. 90, 12; Bell, P. H. Barg, W. F., Jr., Colucci, D. F., Davies, M. C., Dziobkowski, C., Englert, M. E., Heyder, E., Paul, R., and Snedeker, E. H. (1968), J. Am. Chem. Soc. 90, 2704; Franz, J.,Rosenthaler, J., Zehnder, K., Doepfner, W., Huguenin, R., and Guttmann, S. (1968), Helo. Chim. Acta 51, 218; Kahnt, F. W., Riniker, B., MacIntyre, I., and Neher, R. (1968), Helv. Chim. Acta 51, 214; Potts, J. T., Jr., Niall, H. D., Keutmann, H. T., Brewer, H. B., Jr., and Deftos, L. J. (1968), Proc Natl. Acad. Sci. U. S. 59, 1321). This material migrates as two components on disc gel electrophoresis but preliminary studies indicate that these components represent oxidoreductive changes, not involving the methionine residue, of a single component. The ease and economy with which procine calcitonin can be isolated by the procedure described make feasible the production of gram quantities of the hormone under industrial conditions, which would satisfy present research and potential future therapeutic needs. © 1969, American Chemical Society. All rights reserved.