Dr . Marianne GrUnber&-!4an8&0
Dept. of Biochemistry
Institut aiologie

Vhys ico- Chimique
13 Rue Pierre Curie
Paris lf, France

Dear Marianne:

About transnucleotidation reaction--nothing more was ever done be-
side chat preliminary stuff of Heppel's.
looking into it again, but certainly not extensfwly,at least not
in the near future.
longer valid.

Actually, I my be

I don't know why Paul said he thought it no

In the next few weeks I'll be writing up srsenolysis elrperimnfs
and will send you a copy of the very first draft as soon as it is
ready.  Off hand it is still difficult to decide about mechanism.
The oligonucleotides stimulate 58-fold or more, under sptirual con-
centrations. The enzyme alone will slowly arsenolyee however, so
re uiremnt is not absolute by any means.
28&260 greater than 1.6 and heated enzyme dues not stirmfate the
reaction. Actually it inhibits somewhat. Enzyme is the 300-fold
purified stuff.

The enzyme has a

We have dons quite a bit oE kinetics on the reaction,  and these
experiments show that the binding of diphosphate and primr to the
enzyme are related ewnts.  Furthermore the kinetics definitely
indicate one enzyme for a11 the diphosphates. GDP behaves like
the others in all respects except for requirSng a little wre
arsenate for optimal reaction.  Tentatively L wauld say that XIFIP-E
is unlikely, et least starting from nucleoside diphosphate.
other hand this presents difficulties in interpreting transnuoleo-
tidation, unless one postulates that you can gat an
plex starting from polymer.

   On the


enzyme com-

This Is not, of course, wry satisfactory.

Have you heard anything from Lfttausr about recent S-RNA-polynucleo-
tide phosphorylase exper Lment s?

-2-

Sorry that I won't be at Gordon Conference.
a little too close for baby'e arrival.
here for a day or so?

It le cutting thlnge

Can't we get you down

Mot regarde,

Maxine Singer