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The Maxine Singer Papers

Letter from Leon A. Heppel to Maxine Singer pdf (202,349 Bytes) transcript of pdf
Letter from Leon A. Heppel to Maxine Singer
Dear Maxine --
Item is handwritten.
Number of Image Pages:
4 (202,349 Bytes)
Date Supplied:
28 December 1957?
[Heppel, Leon A.]
[National Institutes of Health (U.S.)]
[Singer, Maxine]
Original Repository: Library of Congress. Maxine Singer Papers
This item is in the public domain. It may be used without permission.
Medical Subject Headings (MeSH):
Exhibit Category:
Nucleic Acids, the Genetic Code, and Transposable Genetic Elements: A Life in Research
Box Number: 1
Folder Number: 1
Unique Identifier:
Document Type:
Letters (correspondence)
Physical Condition:
Series: Correspondence, 1955-2004, n.d.
SubSeries: Chronological
Folder: 1955 November-1957 December
Dec 28
What a lovely Christmas present! I was certainly surprised and delighted to find a copy of the "Sandburg Range" under our tree -- such unexpected fun! Bill Bowen has a copy of a book called, I believe, "Lincoln Reader" which also consists of selected writings of Carl Sandburg and I've read a few excerpts. They were quite enjoyable. You didn't indicate where the time for reading the book is to be found. Its deceptive to state that it can be done in small portions for the same total amount of time is involved. It's times, as you suggest, that some of it would be read to David during time all allotted for the children, but he wouldn't stand for the poetry sections.
I hope that you are having a wonderful time in the islands. In a way it's too bad that your trip didn't happen to have occurred in January or February when the weather in Washington is bitter and cold. Actually, we've had some balmy, sunny days and some more beautiful sunsets. February will be another story. That's the time to get away.
The boys were wonderfully excited Christmas morning and quite pleased by their presents. David to two "Hardy Boys" books, an HO train set, a fishing rod, several plastic models, an Ivy League shirt (of which he's fond), an aeroplane which rotates on a rod under some mysterious electronic control. Alan got a Roy Rogers chuck wagon set, a Roy Rogers stage coach set, a "Sad Dog" piggy bank, a plastic tea set, a set of cooking utensils, fishing rod, a book on "Bambi". David also got a record of "Around the World in 80 Days". This rather respectable haul results from having three uncles and four aunts and also from the fact that both boys also have birthdays in December.
I've been working terrific hours this past week and cut my
sleeping to seven hours. I find I bear up quite well as long as I'm rude to visitors and don't answer the telephone. Interuptions, not work itself, exhausts a person.
On the whole the experiments have turned out quite well. The results are as follows:
The nonnucleo[?] tides resulting from alkaline digestion of polynucles[?] tide made with GDP + pApA or GDP + pApApA are surely[?] the mixed 2' and 3' isomers. They are split by seven [?] are but out[?] by bull semen 5-nucleotidase and they have the right PF in 2 bands C80A and I.P.NH3. Geanosine[?] derived from one "end group" can just barely be detected, with the nucleolite[?] lamp its bluish rather than black and blends in with the background. pAp from the "front end" of pApApGpGpG hasn't been looked for as yet. A complication is that GDP and GMP are trapped with "orgin material" and I'm not sure that pAp resolves when mixed with these. I've thought of irebating[?] GDP + pApA and polynucleus[?] tide phospholase[?] and then adding GDP ase and 5-nucleotidase, forming gerasine[?] from residual GDP and GMP. It should be practical.
These genosine[?] polynucleotides are interesting. They don't precipitate out of the incubation mixture, yet their solubility in water is never limited. Elutia[?] off paper is difficult and they precipitate in the tube containing eluting[?] fluid. Apparently salts retained[?] in the chromatograms help dissolve the material of Rf =0 and subsequent didat[?] by the eluting water given precipitation. Some of the material never does elute even with hot water or NH3. By chilling the elution fluid one obtains a beautiful cryptallic precipitate. Markham has observed this for G containing [ . . . ] tides. Maybe PO4 = GDP helps keep the material in solution.
With pApApA and GDP one gets material of Rf=0 and two other bands of low Rf. The slower moving gives mostly AMP, 2' of 3' with alkali and just a little GMP, 2 of 3. The faster moving bond gives AMP, 2' of 3', no detectable GMP, 2' of 3', and faint densities for guanosine[?] and pAp. Presumably it's pApApApG.
GDP= 1.5 moles/0.1 cc, so reaction proceeds up to 70% completion. Quantitative serial chromatograms in process. No visible changes for GDP alone. For GDP + pApApA (.36 moles pApApA/.1cc)
40 MIN No origin material in IPNH3 on K[?]-Hems Faint density in K[?]Hems it must be pApApApG. pApApA about 2/3 incorporated.
140 MIN similar - 3/4 incorp.
210 MIN nearly all incorp. Intense origin density - still a lot of pApApApG
This run shows that no saturation for pApApA has been achieved, most likely. Saturation is at least 0.0036M. With latest batch of GDP there was no reaction without primer, even at 0.06M. With an older lot, there was indication of a rise in P: after a lag.
12-26, 12-27, 12-25 -- repeated runs were made with purified venom on "origin" material and (?) pApApAG. Products are 5'-GMP and 5'-AMP -- further evidence on their identity. 5'-GMP appears to be released first, but its hard to get the enzyme level just right.
12/24 GDP = 0.025M, with and without pApA (.21 [>] moles pApA per 0.1 cc) Chromatogram shows perhaps 1/3 -- 1/4 of pApA still present after some hours. At least 5 units of G are added/ molecule prima-maze more.
12/23 Mon Enzyme fraction 415.7 tables, 35', 2 hours, 4 hours. GDP=0.015M Results show stimulation by 0.0013M pApApA. With 0.0004M [ . . . ] get no simulation at 35', 2 hours and at 4 hours got a little rise 9.25 [ . . . ] 1.1cc).
With ApApUp (0.008M as [ . . . ]) got absolutely nothing. With mitosis[?] polyA got no effect. With pApApA and enzyme varying 0.003 1 -- 10, 0.005cc 1 -- 10 and 0.015cc 1 -- 10 got fair enzyme-rate proportionality.
12-21 -- Sat Tested adevase for Herb and mode "G polymer" with pApA and pApApA for alkali treatment.
12-20 -- FRI You helped set this up but left before seeing results. Sa 150 Enzyme. Poly A and ADP same as usual. ApApUp at 0.0008M (always as compound itself) get stimulation not quite as good as poly A at 0.1 mg for Oila imimix[?], but still very good. Michelnas[?] poly at 0.15mg/0.1cc was almost negative. ApApUp at 0.0002M was perhaps 2/3 as good at 0.0008M.
Now that I've gotten used to the idea that ApApUp, which apparently isn't incorporated, really stimulates the reaction it's beginning to fascinate me. As usual, no incubation mix was used obviously viscous except the two with ApApUp and they were really viscous. How can a compound like this act to stimulate the reaction?
We're spending Mon. and Tues in Ephrata. The boys are quite excited about the visit. David looks very sharp in a new Ivy League shirt, of which he's very proud.
The Ann. Rev. article still wasn't finished when I left. In 3 1/2 days Rose managed to type exactly 18 pages -- an awful record. I got disgusted and typed up the Fed. Abstract myself. Following your suggestion, it mentions nothing a bout stimulation -- only incorporation data and [. . .] results.
Thanks again for the lovely book. I plan to delve into it while up here in Penna. and read out of it to the boys.
Best to Danny
Sincerely Leon
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