E. Vanlieshout et Ma. Hemminga, NMR-STUDY ON THE BINDING OF D(GGAAATTTCC)(2) WITH A POSITIVELY CHARGED PENTACOSAPEPTIDE, Biochimica et biophysica acta, N. Gene structure and expression, 1442(2-3), 1998, pp. 137-147
To obtain a better understanding of the electrostatic nature of protei
n-nucleic acid interactions, we have investigated the interaction of a
double-stranded decamer d(GGAAATTTCC)(2) with a synthetic arginine an
d lysine-rich pentacosapeptide (Pep25), using NMR and optical spectros
copy. The chemical shift data of the decamer under various experimenta
l conditions show that the binding of Pep25 changes the conformation o
f the decamer in a different way, as compared to the conformational ch
anges induced by a variation in temperature or ionic strength. The che
mical shift results are interpreted in terms of ring current effects t
hat emerge into a model for the conformational change, in which the do
uble-stranded helix of the decamer undergoes a decrease of twist and r
ise to accommodate Pep25. The binding results indicate that the positi
vely charged arginine and lysine side chains of Pep25 not only have a
stabilising electrostatic interaction with the negatively charged back
bone phosphates of d(GGAAATTTCC)(2), but also that a stabilisation of
the base pairs of d(GGAAATTTCC)(2) by Pep25 takes place. (C) 1998 Else
vier Science B.V. All rights reserved.