Chemistry Reference
In-Depth Information
and the positively charged peptide or to the reactivity of the Lys residues. Variation
of the central residue did produce some change in binding affi nity. The binding
constants increased in the order Ru-KWK
Ru-KYK. Even though the
Trp residue was expected to contribute more in binding affi nity through intercala-
tion, probably it was not ideally positioned since tethered peptides are constrained.
The differences observed in crosslinking were quite small as the central position in
the peptide was varied.
<
Ru - KAK
<
12.2.5
Protein Fragments
In some cases, intact DNA-binding protein fragments with individual recognition
properties were chosen for conjugation to the transition metal complexes. The aim
was to construct a sequence-specifi c chimera in which the peptide recognizes its
cognate DNA sequence.
M.Y. Ogawa and his coworkers
44
prepared a chimeric metallo-bZIP protein
(Figure 12.5), (GBR-CC)Ru, in which [Ru(bpy)
2
(phen - IA)]
2+
(phen - IA =
N
-
Figure 12.5
Computer generated model of the synthetic metalloprotein of the designed
photoactive DNA binding peptide developed from the crystal structure of cFos-cJun bound
to DNA. (Reprinted from
Inorg. Chim. Acta
,
300-302
, Lasey R.C, Banerji S.S., Ogawa M.Y.,
Synthesis and characterization of a sequence-specifi c DNA-binding protein that contains
ruthenium polypyridyl centres, 822-828. Copyright 2000, with permission from Elsevier.)
