Re: Q: Helix dipoles

peter Murray-rust (
Fri, 15 Mar 1996 14:09:29 +0000 (GMT)

On Fri, 15 Mar 1996, Cristina Cantale wrote:

> On 4/3/96 you wrote:
> .....
> ........
> So, I think that alpha-helix in this example has a greater dipole moment
> than the 3-10 helix.
> In the proposed approximation, the total dipole moment in an helix is the
> sum of the contributes coming from the dipoles present in each AA.
> The dipoles coming from the C-O and N-H in each AA are parallel to the axis
> of helix if this is an alpha elix.In 3-10 helix, C-O and N-H bonds of each
> AA form an angle with the axis, so just a componet of each dipole contribute
> to the final value.
> Cristina

Thanks very much Cristina - I am sure this is an important effect. (we
would need to know the angle and presumably the effect would depend on
cost(theta) - theta being the angle with the axis.

I think there may be another factor as well... any ideas?


Peter Murray-Rust, Glaxo Research & Dev. (; (BioMOO: PeterMR)
Birkbeck College,, CBMT/Daresbury,