In this letter to his former mentor Severo Ochoa, Kornberg discussed the various challenges involved with using different
yeast cultures as sources for enzymes.
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1949-01-24 (January 24, 1949)
New York University. College of Medicine
Original Repository: Stanford University Libraries. Department of Special Collections and University Archives. Arthur Kornberg Papers
Reproduced with permission of Arthur Kornberg.
Medical Subject Headings (MeSH):
From Physician to Enzyme Hunter, 1942-1953
January 24, 1949
It seems like a long time since I've written you, but very little has happened to be worth writing about. First, we want
to thank you for returning the Senate Zwischenferment which was very embarrassing but helpful to us. Since that time, Bernie
has found extraction conditions for the Anheuser-Busch yeast which give him adequate Zwischenferment activity and have a usably
low cytochrome reductase blank. I hope you have received the Zwischenferment we sent you in "exchange" and please
tell us when you run low because we have a good deal of this material and are making some all the time. Also, if you should
need some of "the" old Senate sample, we have almost 100 million grams of it and could spare most of it.
I have been spending all my time in the very painful operation of going back over the DPN synthesis work to repeat experiments
and fill in details. It has been unusually trying in places but everything seems to have worked out rather nicely. It seems
that different batches of the same yeast require different lebewsaft conditions for optimal yields of this activity. The
ATP assay also proved annoying until we found that the hexokinase had to be free of "old yellow enzyme activity" and
Zwischenferment free of phosphogluconate dehydrogenase activity. We also try to get inorganic pryophosphatase free of other
phosphatase activity from several sources, including yeast and potato, but gave it up. The FAD-synthesizing enzyme appears
to be a good deal weaker than DPN-synthesizing activity and the purification problem more difficult. The preparations are
still too crude to permit study of mechanism.
Your biotin data are really exciting. It goes without saying that I would be delighted to cooperate in any way possible.
Do you recall that when you were with us last September you suggested at that time that I look for an effect of biotin on
this DPN enzyme. I tried folic and biotin with negative results, but such preparations might be worth analyzing for their
Our little one is getting to be quite a fatty and a very well behaved youngster, but it still keeps us hopping to keep up
with both of them. No news about Ohlmeyer since I last wrote you. Our fondest regards to you and Carmen.