We present a quantitative experimental demonstration of solvent-mediated co
mmunication between noncontacting biopolymers. We show that changes in the
activity of a solvent component brought about by a conformational change in
one biopolymer can result in changes in the physical properties of a secon
d noncontacting biopolymer present in solution. Specifically, we show that
the release of protons on denaturation of a donor polymer tin this case, a
four-stranded DNA tetraplex, (DNA) modulates the melting temperature of a n
oncontacting, acceptor polymer [in this case poly(A)]. In addition to such
proton-mediated cross talk, we also demonstrate counterion-mediated cross t
alk between noncontacting biopolymers, Specifically, we show that counterio
n association/release on denaturation of native salmon sperm DNA (the donor
polymer) can modulate the melting temperature of poly(dA)poly(dT) (the acc
eptor polymer). Taken together, these two examples demonstrate how poly(A)
and poly(dA)poly(dT) can serve as molecular probes that report the pH and f
ree salt concentrations in solution, respectively. Further, we demonstrate
how such through-solvent dialogue between biopolymers that do not directly
interact can be used to evaluate tin a model-free manner) association/disso
ciation reactions of solvent components (e,g., protons, sodium cations) wit
h one of the two biopolymers. We propose that such through-solution dialogu
e is a general property of all biopolymers, As a result, such solvent-media
ted cross talk should be considered when assessing reactions of multicompon
ent systems such as those that exist in essentially all biological processe
s.