UNIVERSITY

 

Pirrressceret |
WASHINGTON (Zgh

SCHOOL OF MEDICINE

SAINT LOUIS

THE EDWARD MALLINCKRODT
DEPARTMENT OF PHARMACOLOGY

EUCLID AVENUE AND KINGSHIGHWAY February 10, 1958

Dr. Joshua Lederberg
Department of Medical Genetics
Genetics Building

University of Wisconsin
Madison 6, Wisconsin

Dear Josh,

Here are the extracts and a sample of novobiocin. I am
embarrassed about the time that has crept by since I was in
Madison. I made the first extract right after Christmas
but worked it up in a relaxed fashion. When it turned out
‘to be a dud, I did the next one more hastily. I am enclosing
four tubes, each dried from 5 ml. of solution. The source
and content of acetylamino Sugar nucleotide is marked on
each tube. Each tube represents the extract from cells
obtained from 500 ml. of culture (about 1.3 Gm packed wet
weight). For future reference, I have previously removed a
duplicate 5 ml. from each tube I am sending to you. However,
you can have these samples whenever you need them, or I can
make more.

I thoroughly enjoyed the afternoon with you. The
possibility of getting at the compounds in the "other"
sequence (s¥ through the mutant approach intrigues me. Two
things we didn't discuss occurred to me later; It is
possible that the small amount of residual dye from the
crystal violet extracts will be bacteriostatic. This dye
separates well from some of the interesting compounds on
electrophoresis. I could easily prepare from the extracts
whenever desirable electrophoretic strips (1/2" wide?, 1"9,
2"?) which could be overlaid with agar. This latter technique
might be interesting in any case. Similarly, these extracts
have all been through a cold TCA precipitation which might

’ destroy labile compounds. The extracts can also be prepared
with boiling water at neutral pH, which might be less harmful.

Thanks very much for the cultures. They all arrived

safely. I assume the TLB auxotroph is a théonine, leucine, 7LB
biotin auxtroph, Neither I nor Dave Hogness understand the /

terminology DaP-prototroph. Does this refer to a primary
isolate as contrasted to a DaP-auxotroph obtained in the DAP
laboratory? So far I have done nothing except transfer the

cultures. I think I can get to them next week, so I may

have some more news Shortly. Guy Barry sent me a culture of

Ko351l+0, the coliminic acid producing strain, so I don't need

to trouble you for it any more,
Dr. Joshua Lederberg
February 10, 1958
Page 2

Thanks also for Kandler's paper. It does not change my

feelings about $, aureus. Two major criticisms are:
1. The method of preparation of walls in NaQH would undoubtedly
destroy walls of cells like §. aureus (@f Mitchell and Moyle).
I can't be- sure without seeing the paper in press that these
are walls. 2. The occurrence of a normal amount of DAP in
hydrlysates of whole cells might only indicate the presence of
DAP precuSors, such as we might find in the organisms you sent
us. Ina more general way, however, possibly the point of
gnterruption Oe Coit wall synthesis is not exactly the same in

- probus and §, aureus. In fact the data do indicate that the
"walls" of the "insteble" form have lost some accessory structure,
as contrasted to the basic structure. They may be very incomplete
"walls", and again inhibition of some wall "polymerase" might be
implicated. However, as T said, the idea that a uridine nucleotide
transglycosidase is specifically inhibited is only one interesting
hypothesis, and possibly some general property of the membrane
is interfered with by penicillin having a Slightly different
effectg# in the two organisms.

Novobiocin inhibits at a point different frcm penicillin.
It seems to be closer to crystal violet, and we should know
exactly in about a week.

I'm delighted to hear you'll be coming in May.

 

Sincerely,

JLSt:ab