Biology Reference
In-Depth Information
3.2.3
Complexation-Induced Chiral Assemblies of
Ferrocene-Peptide Bioconjugates
Metal ions have been known to exhibit a variety of properties in
proteins, one of which is structural stabilization for biological
function [20]. Metal ions also play a crucial role in the redox processes
of proteins [20]. The incorporation of metal coordination sites into
peptides has been investigated on the stabilization of secondary
structures [21].
The complexation with metal ions is envisioned to stabilize and/
or regulate secondary structures of peptide chains. The ferrocene-
peptide bioconjugate bearing the dipeptide chains of homochiral
sequence (-L-Pro-L-Ala-NH-2-Py), which is characterized by the
chirality organization through two intramolecular interchain
hydrogen bondings as observed with
1
, forms the 1:1
trans
palladium complex
to stabilize the chirality
conformational regulation in both solution and solid states (Fig.
3.10) [22]. The single-crystal X-ray structure determination of
8
8
with PdCl
(MeCN)
2
2
reveals the pseudo-helical conformation through palladium
coordination and chirality organization based on the preservation
of the intramolecular interchain hydrogen bonds as depicted in Fig.
3.10 [22].
O3*
O
N3*
N
N
H
O
N4*
O
O2*
NH
N
O1
N1
Me
N2*
Fe
Fe
Cl
Pd
Cl
Cl2
Me
Pd
O1*
N
N1*
NH
N2
Cl1
O
O2
O
H
N
N
N4
O
N3
O3
Fc(- L -Ala- L -Pro-NH-2-Py) 2 PdCl 2 8
Figure 3.10
Molecular structure of the palladium complex
with the
ferrocene-peptide bioconjugate bearing the dipeptide
chains (-L-Ala-L-Pro-NH-2-Py).
8
bearing the one
dipeptide chain of the heterochiral sequence (-L-Ala-D-Pro-NH-
2-Py) forms the 2:1
The ferrocene-peptide bioconjugate
6
trans
palladium complex
9
[23]. The chirality-
organized structure of the palladium complex
9
is present in a
 
Search WWH ::




Custom Search