Professor Leo Sl;il.ard

DearLao,

Dr* Howard Green has been kind emugh to e%i_d me, ths copies of your two
new papera, aa yma had requested, and I have read them with much interest.

f have never made a thorough srtudy of the problem of induction of enzyme
formation, and for this reeeou it i8 not poeeible for me to speak very -
eignificantly about your first paper*  I agree with you that it is possible
that an orgmism might have euoh a nature as to permit, for a particular
enzyme, the enzyme level to be either low or high, and I think that it is
well worth while for you to have made ycmr analysis of the problem, per-
mitting you to reauh this conclusion.

On the other hand, I remain pretty skeptical about the application of this
idea to antibody formation, although eomething of this sort is without
doubt involved in the manufacture of gamma globulin or other antibody pre-
cursors.  I think that experimental results obtained during the last twenty
years have not changed the situation very muah from that which existed in
3.940, the time of publication of my paper on a theory of the structure of
antibodiee and the nature of serological reactions.  I still feel that the
antigen molecule or a portion of it containing the hapten serves as the
template for the combining regions of the antibody molecules, and that
special mzymes or genes are not involved in the manufacture of different
antibodies.  The ability of the rabbit to manufacture antibodies against
a haptenic group seems to be determined by the chemical nature of the
haptenic group, and not to show the hit-or-miss character that might be
expected in caee that different genes and enzymes were required for dif-
ferent antigens.  Moreover, it seems to me inexplicable on the basis of
the non-tsarplate idea that animals should be able to manufacture highly
epeaifie antibodies again& haptenic groups that do not occur in nature,
and that do not reeemble closely molecules that occur in n.xture,  Moreover,
if different genes are involved in the manufacture of different an-t$bod~es~
we would sxpect that the amino-acid composition and sequence for the dif-
ferent antibodies would in general be different, whereas in fact they are
found to be the came, to the extent that they have been investigated,

I have published about a dozen papers on antibodies, mainly the discussion
of experimental work carried out in our laboratory, but the reprints are
exhausted.  I have, however, found an extra COPY of my first paper, which
I enc1086.

With best regards, I am

Sincerely your8,

Linus Pauline:jh


Proferasor Lea Seilwd
Page 2 '
25 January 1960

P.S.  Please let me know what you think about the arguments that I have
given above, in particular, the one about oonetanay of amino-acid com-
position and sequence.

Ava Belen joiner me in aending best wishes to you.

L. P.