October 6, 1956

Dr. J. T. Park
Walter Reed Army Medical Center
Germfree Research Unit

' PWashington 12, D.C.

Dear Dr. Park

I was wery pleased to have your letter of the 4th. I had no notion of
how far you had carried your chemical, conclueions recently on the action
of penicillin, Your work is usundly quoted (or so I have thought) as
bearing on nucleic acid mtabolism; of course it was done before the
more general sigaificenos of youx compounds could be realized.

It would be just fine 1f we could get together an publim tion. I've sent
the short note of which you hava a copy to J. Bact. the pleasantest thing
I could think of is that you and Stromlnger draw up a companion version,
and we'll arrange for them to follow one another in the Joumnal, as I an
confident man be arranged.I'll ask Porter to hold mine up to wait for yours,
though it would be better if you could newex fast enough to avoid having
to disturb the editorial routine, Let me knew your pleasure.

I have a thought on why other organiams don't seem to accumlate the
UDP's—— tape staph is lucky (for you) either in holding together a little
longer in the presence of penicillin, or in the persistence of the
presursor-forming system in the incipient lyaates. It should be possible
to demonstrate the UDP's more generally under the influence of penicillin
with calls (i.e., protoplasts) which are protected by sucrose. You ani.
Marv have probably had a chance to get together on this—- I don't know his
immediate plans, but suspect this is on the agenda; anyhow I'm sure you can
work that out yourselves.

At the moment, I'm mainly interested in protoplasts am L-forms as tools
for genetié work (e.g., donors and recipients of genetically active DNA)
but none of this has worked out positively at all, so far. We have gotten
E. coli to grow as L-colonies, with some difficulty, but first triala give
no bidioation that mixtad cultures will interact any differently in the L-form
than they would as bacteria: e/g. no recombination, presuambly no fusion,
of two Hem F- strains.

Yours sincerely,

4 Joshua Lederbe rg
f

Ww