Chemistry Reference
In-Depth Information
O
O
OH
aq. pH 8.0
1 mol% dendrimer
L2K7
25°C, 3 h (99%)
NO
2
O
H
NO
2
HN
H
3
N
H
3
N
O
NH
N
O
HN
O
N
HN
H
H
2
N
O
O
O
NH
NH
H
2
N
NH
2
O
NH
2
NH
2
HO
O
HN
HN
HN
N
HN
O
HN
N
O
O
H
O
N
NH
O
H
OH
H
2
N
O
O
HN
HN
O
O
NH
H
2
N
NH
2
HN
H
2
N
O
HN
HN
O
N
NH
O
O
N
O
O
N
O
N
O
H
H
H
H
O
O
HN
H
O
OH
HN
O
NH
O
N
H
OH
O
NH
3
H
2
N
NH
H
2
N
O
OH
H
2
N
HN
O
N
H
O
L2K7
NH
HN
O
O
H
HN
O
NH
NH
3
NH
3
FIGURE 15.5
Aldolase dendrimers with N-terminal prolines catalyze aldol reaction with a
multivalency effect.
(AcTyrThr)
8
(DapTrpGly)
4
(DapArgSer)
2
DapHisSerNH
2
catalyzing the hydrolysis of acyloxypyrene
trisulfonates. Its catalytic site consists of two cationic arginines at position X
4
for
substrate binding and one nucleophilic histidine at the core position X
2
for
ester cleavage (Figure 15.2) [18]. Structure-activity relationship studies showed that
the catalytic proficiency
The first case concerns peptide dendrimer
RG3
k
cat
/K
M
for the hydrolysis of ester
1
increased in the
(AcArgSer)
2
DapHisSerNH
2
! RG2
(AcTrpGly)
4
(DapArgSer)
2
DapHisSerNH
2
! RG3
RG0
AcArgSerAlaHisSerNH
2
! RG1
series
. Addition of the outer dendrimer
branches containing aromatic residues lowers the K
M
values (stronger substrate
