The enclosed manuscript is the best introduction to the purpose of this letter. The paper will be published as a communication
in the Journal of Biological Chemistry late in December.
In short, we have concluded that the particular properties of the interaction between fl histone and SV40 DNA relate to the
superhelicity of the DNA. The increased ability of the fl histone to complex the DNA, relative to the other histone fractions,
disappears when the supercoil is destroyed by nicking.
We are interested in testing how quantitative the relation is. That is, is the curve of fl histone concentration against the
percent of supercoiled DNA complexed, a function of the extent of the supercoiling? Thus, we would like to repeat the experiments
on a series of molecules identical except for the extent of the supercoiling. We realize that this is analogous to experiments
you have recently published.
Therefore, I am writing to investigate the possibility of obtaining from you small samples of such a series of molecules.
Our work requires that the DNA be radioactive and I do not know if you have labeled material available. Your published work
is all with unlabeled materials. We could probably do the basic experiments if about 2 [micrograms] of each DNA were available
to us, depending on the specific radioactivity. We would be able to do a more thorough job if we had as much as ten [micrograms].
We would like, ideally, to look at several molecules with a spread of values of superhelix density.
We will be looking forward to hearing from you. We would of course be most grateful if you were able to help us out. We will
also be grateful for any comments you have on the enclosed manuscript.