ecta.1 ,Test of


J the Framework Theory of Antigen

     Antibody

The framework theory (latt?.ce theory) of serological precipitation
-
-

and agglutination, first proposed by       has not been accepted

`r jy all investigators in the field, although it is supported more or less

strongly by a considerable body of evidence

out some eqeriments which correspond so v?ll in their results with the

predictions of this theory as to leave little doubt of its correctness.

Ye have synthesized a substance which gives a specific prec'ipitate
    r

with a mixture of tea different antisera, but gives no precioitate vith
                                                                  A_

either antiserum alone.  The substance contains two different hsptenic

groups, R and X, to which the two antisera are homologous: the anti-R

serum was made by injecting rabbits with asoprotein containing R groups,

and the anti-X serum by injecting bith szoprotein containing X groups.

  --_-_--------------------------------
'>,..:.' J. R, %rrack, "The Chemistry of Antigens
  No. 194 of the Med5.ca.l Research council, and Antibodie$QReport
                          Eis Kajestyls Stationcry Cffice,
   London, 1934; Second Edition, Report Uo. 230, 193S.
   2~1, Hei,delbereer an                 Red.,       -'> /'3>t"
                            ?; 559, 56_; "*
   62 - 467, 69;>Q935 F. B. Kendall, J~"&ptl.
   4       ; 14. Heidelberger, kern. Rev., A; 323,$193
                   +            .
                        I                        --   6
w L, Pauling, J'%I. Chem. Sot., &i 2643,$1#0~.
1. 4;' ii. Fauliog,
  J'        Cavid Pressman, sari II. .samp`Efell
u&L{. , 64; 2994, 3003,


The 9 .m.d X groups were respectively the p-- n zophenylarsonic axid. groq

and the r-aeobenzoic acid group,  and the RX substance used in most of


our work w.s l-amino-' ,-E-(E-azophenylszo)$~enylarsonic acid-3,6-di-
sulfonic acid-7-E-(E-azo+enylazo)banaoic acid-ELhydroxynaphthalene.

Similar re cu!. t, F werf. also obtained with 1 ,&dihydro-q-2-s-azcphenyl-
arsenic acid-3,Ld.i sulfonic acid-?-r-(-o _-nzo~~enylaxo)benzoic axi.?.-

na~hthalene .

The eqerimenta.1 results show that in the formation of the precinitste

both of the tvo haytenic groups of the molecule enter into specific reaction,

the R group 14th an anti-R antibody nolecule
                 / and the X gr0u-o with an

anti-X antibody molecule.  This is shown by the fact that the RX substance

precipitates only with a mixture of the two antiserR, and not with either

one alone; the explanation of the failure of -n-
                            ,,ecipitation with only one

antiserum given by the framework theory is that with respect to either

antiserum the RX molecule is only monohaptenic and hence only univalent,

and so can not act as the link betl,reen antibody molecules in the formation

of a f ramerrork.

Vith the effective bivalence of the Trecipitating antigen thus proved,
                                                                     . .

kncwledf,cre of the zntibodg-antigen molecular ratio Icr the 3rscioitate

provides the velue of the average valence of the antibody molecules.

The molecular ratio has found by analysis     0.7, which corresponds to

2/(?.7 7 2.E; for the average antibody        If the a.ntibody k:iere

-T`------`--`-`-`^-`"---`-`-""-'
8imllar values of the antibody-antigen nolecular ratio have been
     reported (J$e& 4) for Trecipitates of anti-R antisera
and siqle substances~ containing two or more B hqtenic groups.


3

univa.1en.t the molecular ratio would have the value 2, >hich is fizr

greater than the experimental value.  Further evidence for the effective

multiva,lence of antibody is provided by the observation that the RX

preci-oitate is soluble in excess of the mixed antisera; this solubility
ca$ot be explained on the basis of univalent antibody.
  ' A detailed account of this work will be published in the Journal

of the American Chemicel Society.
~~ __._ -a--,_ ---.  -(                 

                         Lirzs Paul ing
                                                                    -
                                                             4-+-      *u-
                                    David P re s sman
                                                             P"
              Dan;. &&ell
                                                                       <,,,..i.
   q #"'                                                    ..-          @`C
c 4.L 1 Gates and Crellin Laboratories of
    Galif ornia Institute of I'echnology Chemistry)