THE PUBLIC HEALTH RESEARCH INSTITUTE
OF THE City OF NEW YorKkK, ING.

Foot OF East 15TH St., NEw YorK 9, N. Y.

TEL. OREGON 7-4411

July 17, 1958

Dr. Joshua Lederberg

Professor of Medical Genetics

University of Wisconsin School of Medicine
Genetics Building

Madison 6, Wisconsin

Dear Josh:

Thank you very much for your letter and the excellent
suggestions. The problem of polymers as substrates has been ex-
tensively discussed by our committee and is of course one of the
most difficult problems we have to deal with in regard to an inter-
national unit. Actually in the note in Science we suggested mea-
suring the product of a reaction such as catalyzed by phosphorylase
which is an expression of the number of linkages split or formed
(e.g., 1 glycosidic linkage synthesized per mole of Pi liberated
from glucose-l-phosphate), but what are we going to do with an en-
zyme such as lysozyme? We must hope that soon someone will make a
synthetic substrate for it.

The suggestion for the selection of a simple name for
the unit which can be readily abbreviated is an excellent one. TI
hope you don't mind that I am turning over your letter to Dr.Sidney
Colowick, who is one of the American representatives on the Inter-
national Committee on Enzyme Nomenclature which will take up the
problem of an international enzyme unit during the meetings in
Vienna. In case you should have some good suggestions regarding
an easy name for this unit, both our committee and theirs Will ap-
preciate hearing them.

I enjoyed reading your comments regarding the moon
problem and I am glad you have such an excellent response to your
efforts.

With best personal regards,

Sincerely yours,

Efraim facker, M.D.

Chief, Division of

Nutrition and Physiology
ER/k

(7 ‘9277 0Y/

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