February 16, 1965

Dr. Marianne Grunberg-Manago
Department of Biochemistry
Institut Biologic, Physico-Chimique
13 Rue Pierre Curie
Paris 5e, France

Dear Marianne:

This letter has been written often, in my head,  but as usual time

flies,  In spite of my silence, the various parcels you sent around Christmas
time were received, and enthusiastically, The children love the records, and
are acquiring good French pronunciation from them.
American school system will eventually spoil them!
the ''cookbook" and will probably go on enjoying it for many years.
really one of the most delightful things I have ever seen!
for being so vwy nice.

It's too bad that the
All of us have enjoyed
           It is

We all thank you

As you may or may not have heard, the triplet synthesis did go very

well indeed.
Phil Leder and I are workfng on a manuscript describing the syntheses and
the products.

To date, about 20 different triplets have been prepared.

A draft dl1 be ready shortly and we'll send it to you.

The triplets as well as various other things have kept us away from the

phosphorylase stability problem.
started working myself on it--so there is no nws on that front.
Hcward, who had started out to work on it, has instead been studying, using
phosphorylase, various properties of a triple helix of 2 poly U and 1 diamino-
purine riboslde.
phosphorylase, as well as the potassium activated phosphodiesterase are really
very sensitive reagents for the study of eecondary structure.

Only lately have I gone back to it and

Frank

This helix was discmered by Frank and Todd Miles.

The

I have agreed to write a chapter on polynucleotide phosphorylase for a

        This is to described preparative methods for the enzyme,
         I noticed in your recent papers that you have been

new series entitled "Procedures in Nucleic Acid Chemistry," edited by Giulio
and David Davies.
not general aspects.
using Azotobacter enzyme, prepared according to the original procedure
(Grunberg-Manago, Ortie, and Ochoa, 1956) for polymer preparation. Do you
have any comments on the procedure, or growth of cells, or designation of
the cell strain, that Mould up date the procedure as described?
be very helpful in making the article 88 useful as possible.

This would

For the same reasons, I would be interested in any comments on the

-- E. coli preparation you recently published.
point at which one can stop and have enzyme good enough for polymer prepara-
tion, or fa It adviaable to go all tha way through?

In particular, is there any

-2-

Recently we looked, in crude 20,000 x & extracts,  at the relative

       The diesteraee is about 40-50 tfmss more active (for

activities of po1yn;cleotide phosphorylase and potassium-activated phos-
phodiesterase.
polymer breakdown, than is phosphorylase. Neither one is changed appre-
ciably in 2 mutant6 that lack the "ribosomal" Was8 (A-19 of Gilbert and
Vatson, and MBE-600 of Made).

Vhen are you coming for your lectures?

Best regard6 to Armand and

the children,

Yours,

Mutine Singer

MS: peig