CORIXUNICATIONS TO THE EDITOR
March, 1948
1293
A GENERAL THERMODYNAMIC THEORY OF ION EXCHANGE PROCESSES
a weakly dissociated ion-pair is formed (-S03Ag), the corresponding dissociation constants must be Sir: introduced into the expression above ; volume The specific volume of a strong (sulfonic) acid change terms of the form ( P A + VR- - vAR)i resin measured in water with the following cations occur and the expression becomes too complex for in the exchange position is: H+, 1.283; Na+, development within the limits of this communica1.655; K+, 1.434; Cs+, 1.388; Rig++, 1.665; tion. The dissociation constant becomes a funcCa++, 1.585; Ba++, 1.453; Xg+, 1.283. When tion of swelling pressure. This complication apan alkali metal resin is equilibrated with solutions pears in the alkaline earths; the swelling of Mg++, of the same alkali ion, the specific volume de- C a + + and Ba++ resins is directly proportional to creases with increasing concentration, and usually the solubility of the benzene sulfonates. becomes less than the pure water-equilibrated These concepts form the basis of a general volume of the next heavier member of this group.’ theory of exchange processes, applicable also to These and other data, in conjunction with a cationic resins and non-aqueous ~ y s t e r n s ,which ~ simple mechanical model and classical physico- permits predictions of K D from measurable physchemical methods, provide a basis upon which ex- ical quantities. change phenomena may be interpreted. The (4) G. Wiegner, J . SOC.Chem. Ind., SO, 55 (1931). resin is an osmotic system in which the fixed, nonDEPARTMENT OF CHEMISTRY diffusible (anionic) groups act as though restricted POLYTECHNIC OF BROOKLYN INSTITUTE by a semipermeable membrane separating the BROOKLYN, NEWYORK HARRYP. GRECOR inner pore volume ( V i ) from the external solution. RECEIVED DECEMBER 19, 1947 Vi varies with t,he swelling pressures and the elasticity of the resin structure. V, and total resin volunie (V) can be determined by pycnoON THE DYNAMIC STATE OF ANTIBODIES metric1 and other methods.2 Sir : Dry resins swell in water chiefly because of Experiments with N15 labeled amino acids carhydration of the fixed and counter ions and the ried out by Heidelberger, et aL,l have led these osmotic pressure due to the latter. If a salt authors to the conclusion that normal serum proof the counter ion is added to the external water, teins, as well as immune globulins, incorporate Donnan effects virtually exclude i t from the in- dietary amino acids during immunization. Howternal volume; a counter osmotic pressure is es- ever, no exchanges were stated to occur with intablished with consequent reduction in swelling. jected antibody though the authors found an exThe dependence of swelling upon the (calculable) cess of N15 in these substances which was about counter osinotic pressure provides access to the two to four times as high as their experimental $-V relation; other methods may also be ap- error, and about one-fourth to one-eighth of their pli~able.~ value for the active antibodies. Consider the exchange process We have repeated these experiments using C14 leucine in the following manner: AT BZ = A$ + : B A rabbit was actively immunized against p where neither A + nor B+ forms a weakly-dissociated compound with the fixed anion. The azophenylarsonic acid-ovalbumin until the serum had a high titer of the corresponding antibodies. virtual osmotic work for AT + A$ is 6n RT- In Ten days after the last injection (day 1) an injecuA:/uA;, and the virtual V work is GnpVA,+. VA: tion of 10 cc. of concentrated rabbit pneumococcus may be determined experimentally. aiitiseruni (Type I ) was given intravenously, The expressions for B: + B t arc similar, and, followed by a similar injection on day 2 . On the same day, an injection of 30 cc. of a 1% leucine as 6w = 0 solution was givcri intraperitoneally. The leucine contained CI4 in the carboxyl group and had an activity of about 0.06 tnicrocurie per where 9 is of course the swelling pressure. The Similar injections of leucine were given on the separation factor- h - D = aA;aB:/aB:aA; is then three following days, 1.15 g. of leucine being inunity for = This is the case for K + and jected in all. Samples of seruiii were taken on days 5 , 9 and NH4+. K D is not a constant because p and the V’s are not constants; the latter depend strongly 16. The antibodies were precipitated with the upon aA;/aB; in a manner determined by the ionic corresponding antigens, washed with saline (3x), distilled water ( l x ) , alcohol and ether (2x), dried diameters. and analyzed for C”. The results are given in the If the fixed group is weakly acidic (-COOH) or
+
+
vB;
(1) H. Chaya, Thesis, Polytechnic Institute of Brooklyn, June, 1947. (2) R. A. Gortner, “Outlines of Biochemistry,” J. Wiley and Sons, Inc., New York. N. Y., 1938. (3) E Posnjak. Kolloidchem. Beth., 3, 417 (1912).
(1) M IIeidelberger, H P Treffers, R Schoenheimer, J Ratner and D Rittenberg, J B ~ o lChem , 144, 55.5 (1942). (2) The ‘ 2 1 4 used in this investigation was supplied by the hlonsanto Chermcal Co. and obtained on allocation from the U S Atormc Energy Commission. This work was supported by a grant from the Rockefeller Foundation
