November 18, 1943
AIR MAIL
Dr. A.N. Richards
Committee on Medical Research
2101 Constitution Avenue
Washington 25, D.C.
Dear Dr. Richards:
I am leaving for Washington on Sunday, and hope to have the pleasure of talking
to you for a few minutes. I shall arrive in Washington on the afternoon of Thanksgiving
day, and shall attend a meeting of Division 8 of the NDRC on Friday, November 26.
This meeting will, I think, be over by 4:00 or 4:30, so that, if you should be in
town and be free at the time, I could come to your office at 5:00 or 5:30. I have
made no appointments for Saturday; my train leaves at 5:30 Saturday afternoon.
I would like to tell you about an idea which Dr. Campbell and I have had
about penicillin. It occurred to both of us that the efficacy of penicillin might
be increased considerably if it could be held in the blood stream for a longer period.
This might be accomplished by coupling it to a protein molecule, large enough not
to leak out through the kidneys. Human globulin, for example, might be used as this
protein. Whether the coupling could be done in such a way as to leave the effectiveness
of the penicillin molecule unimpaired could be found only by experiment. The work
along these lines could be done most effectively, of course, with knowledge of the
structure of penicillin, but some coupling methods might be tried even in absence
of this knowledge. The possibility also exists that, even though penicillin itself
could not be coupled to protein without loss of activity, some active analog might
be synthesized (after the structure of penicillin has been determined) and coupled
without loss of activity.
We would be interested in doing work of this sort because of our experience
in coupling molecules to proteins. Our blood substitute work is moving alone smoothly
and we are beginning to think about other possible jobs. Our program of work in immunochemistry
in general is making satisfactory progress, but our artificial antibodies, although
they show some productive activity in animal experiments, are not yet sufficiently
effective to be of practical value.
Sincerely yours,
Linus Pauling
LP:jr
