One big difference between snake toxins and cone toxins is the size. The
cone toxins are small peptides (ony 8-35 amino acids long) and so are not
very immunogenic. It is true that an antibody titre can be raised by
multiple small injections of small peptides (this has been done to raise
antibodies to the peptide hormones vasopressin and oxytocin, for example)
but it is unlikely that anyone in their right mind would subject themselves
to a course of conotoxin injections in the hope of becoming immune to them
with time.  For the same reason, there is little interest in developing an
antivenene to cone shell venom - there are over 500 species of cone shells
and each has a different cocktail of toxins in their venom which mitigates
against this approach. Even if it was decided to raise antisera against
Conus geographus (the most deadly cone shell to humans) - and I believe this
was attempted by the US Armed Forces (Navy ?) in the 1960s [I have sighted
the reference but cant recall it right now] there is still the problem of
delivery to the victim in time. On land, following a snake bite,  one can
relatively easily call for help and reach a treatment centre in time whereas
for the rare occassion of a cone shell sting (see
http://grimwade.biochem.unimelb.edu.au/cone/deathby.html) the victim is
usually some hours from assistance often on a remote island or some hours
from medical attention.
----- Original Message -----
From: "Paul Monfils" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, October 07, 2000 3:15 AM
Subject: Re: mollusca Cone snail toxin question


> It is true that one can become immune to snake toxins by repeated
> injections of increasing dosage over time.  Probably the same is true of
> cone toxins.  However, such immunity is not without cost.  It has been
> found that persons immunized in this manner suffered irreparable liver
> and kidney damage in the process, which may well have ultimately led to
> their early demise.
> Paul M.