During her 1954 visit to the United States, Franklin visited many virus researchers who would subsequently collaborate with
her on projects involving virus structures. Barry Commoner sent her samples of a protein he called B8, to compare with the
x-ray diffraction studies of TMV protein. They subsequently published several articles together. In this letter Commoner responded
to Franklin's initial x-ray diffraction findings on the B8 protein.
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1955-03-15 (March 15, 1955)
Washington University. Henry Shaw School of Botany
Original Repository: Churchill Archives Centre. The Papers of Rosalind Franklin
I have gone over the material which you send me with a great deal of interest. Your investigations certainly promise to tell
us a great deal of what we want to know about the relations between TMV and the nonvirus proteins.
Although there are a number of extremely interesting points which I shall want to write you about, this letter will be restricted
to the immediate issue of the paper which you have prepared on your results with B8. After reading your manuscript it appears
evident that a good deal of confusion now exists with regard to the abnormal proteins related to TMV. The facts as I see them
1) TMV-infected plants produce at least two and probably three low-molecular weight abnormal nonvirus proteins which are
immunochemically related to TMV and which polymerize to form TMV-like rods.
2) As noted in my revision of your manuscript, there is agreement on the existence of at least two of the above proteins
between myself, Jeener, and Takahashi's original publication (Amer. Jour. of Botany, 40, 85). The correlations between
my terminology and Takahashi's, with respect to the two proteins, is presented in my revision of your manuscript.
3) Very recently the paper by Delwiche, Takahashi, Newmark, et al. (Biochim. Biophys. Acta 16, 127) claims that only a single
abnormal protein can be found. However, they offer no data to substantiate this claim and the method of preparation which
they use is identical with one of the methods which we have employed to isolate two separate non-virus components (B3 and
B6). Since seeing the Delwiche paper I have been concerned over this discrepancy and have examined the behavior of mixtures
of B3 and B6. We find that such mixtures polymerize to form a single high-molecular weight component which migrates in a
homogeneous fashion in the Tiselius apparatus at pH 7.0. In other words, the two components will form a co-polymer. Our
own preparations of B8 are made by first preparing a homogeneous preparation of B3 and then polymerizing it to form B8. Unless
B3 and B6 are separated before polymerization is induced it is likely that a complex co-polymer will be formed which is difficult
to distinguish from B8. I suspect very strongly that the protein described by Delwiche et al. and which was used by Rich
in his work was very likely such a co-polymer containing both B3 and B6 in an indefinite ratio.
4) For these reasons the "abnormal protein" of Rich and Delwiche should not be considered the equivalent of B8.
Furthermore, if these workers, including Takahashi, are not aware of the occurrence of B6 and its participation in the formation
of a co-polymer, it is entirely likely that successive preparations from their laboratories may contain variable ratios of
B3 and B6. Thus, the preparation which Takahashi has sent you may contain little or no B6 and is, therefore, equivalent to
our B8. We find that B6 is readily denatured when extracts are manipulated and it is possible to lose most of the B6 in a
preparation as a result of lengthy processing. Hence, I would expect that the major variation in the preparations produced
by the other laboratories would be a fluctuation in the relative amount of B6 present in the polymerized "abnormal protein"
and that in some cases the B6 content may be zero without their being aware of it.
I have tried to incorporate some of these ideas in an addition to your manuscript. What I have added is probably unduly long
and I hope that you will feel free to condense it as far as possible. I have also made a few minor changes in the first page
or two of your manuscript to avoid statements which cannot be supported by our own data. This includes Richs' assertion
that the chemical composition of the abnormal protein and TMV are identical. This is a very doubtful statement in view of
the likelihood that their protein is not of constant composition.
Because of the material which I have added to the manuscript I think that it would be wise if my name were added to the paper.
The results are extremely interesting and I am happy for the opportunity to be associated with the publication.
Also included herewith are galley proofs of two papers on the nonvirus proteins which will appear in the March 20th issue
of the JOURNAL OF GENERAL PHYSIOLOGY. I am sending you these now so that you can have some idea of the evidence which we
now have on the numbers and properties of the nonvirus proteins.
Under separate cover I am sending you about 10 milligrams more of the B8 preparation which you now have. After some trials
I decided that the best orientated preparation appeared to be a pellet of the protein spun down in the ultracentrifuge. The
material is being sent to you in this form. I hope that you will be able to get an improvement in particle alignment by forcing
this material into a capillary. In any event, the pellet which I am sending you is the most concentrated form in which I
can prepare B8 and should make your manipulations easier to carry out.
[HANDWRITTEN NOTES:] You can prepare paracrystalline needles of B8 (like those of TMV) by bringing a preparation to pH 3.4.
Can such needles be orientated successfully?
We are very much interested in obtaining good amino acid analyses on this preparation of B8. Consequently, I should like
to ask you to try to salvage as much material as you can from your operations and return it to me when it is no longer useful
to you. Regardless of the physical state of the preparation we can use it for amino acid analysis.
I hope you will write again soon and let me know what you think of the situation. In a little while I shall write you concerning
some of the ideas which I have on the possible relations between the abnormal polymerized proteins and TMV nucleoprotein.
Meanwhile, I shall look forward with interest to learning of your latest results.
[HANDWRITTEN NOTES:] PS. Please feel free to note whatever changes you wish in this and to submit it to NATURE without checking