Chemistry Reference
In-Depth Information
Non-Polar amino acid
(a)
d
n
1
r
3
n
g
|
5
Polar amino acids
(b)
Aromatic and aliphatic groups
(c)
3
.
Aromatic or aliphatic
peptide derivative
Figure 4.1
The structure of (a) 20 natural L amino acids and (b) aromatic and
aliphatic residues that gives rise to (c) aromatic short peptide derivatives,
which form supramolecular assembly through hydrogen-bonding and
p-stacking interactions.
side-chain substitution. There exists an enormous number of possible sequences
to give rise to peptides (20
5
/3.2million sequence possible for a pentapeptide).
Considerable progress has been made in elucidation of design rules of peptides
capable of forming well-defined self-assembled nanostructures.
24-32
Biocata-
lytic peptide hydrogelators are comprised of three components, i) an assembly
directing unit, a component that directs the noncovalent interaction responsible
for self-assembling of the precursor ii) an enzyme-recognition site (peptide se-
quence based on enzyme's substrate specificity), and iii) a molecular switch
component that initiates self-assembly upon enzyme action.
4.4.1.1 Assembly Directing Unit
The simplest and most versatile peptide self-assembly paradigm consists of
short peptide sequences (typically less than five amino acids, and often only
