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DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE

 

PUBLIC HEALTH SERVICE . BETHESDA 14, MD.

 

NATIONAL INSTITUTES OF HEALTH

September 18, 1957

Dr. & Mrs. Joshua Lederberg
University of Wisconsin
College of Agriculture
Department of Genetics
Madison, Wisconsin

Dear Dr. & Mrs. Lederberg:

I am sorry for the long interval of my correspondence.
Did I write to you about the results on enzyme determination
of gal,® When I received the two strains, I tested the enzymes
by a standard method twice. The results showed that both are
leaky in galactokinase and gal-l-p vridyl transferase. How-
ever, as usual it is rather difficult to say "leaky" quanti-
tatively and also there is always a question of contamination
by positive strain ow extract. Another point is that these
strains had an interfering enzymatic activity for UDP Gal-4-
epimerase determination and I could not determine the activity
of this enzyme by our standard technique. These points made
me hesitant to make any final decision on the enzyme distri-
bution of these two strains. Im planning am repeating the
test but I have been involved in other projects. I am hoping
I will be able to get back to the galactose field some day.

I am forwarding to you two manuscripts on the purifica-
tion of gal-l-p uridyl transferase and galactose inhibition
of the growth of gal-l-p uridyl transferase-less mutant.

Sincerely yours,

\KAe per _

KK/mkb Kiyoshi

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