Interaction analyses of amyloid β peptide (1-40) with glycosaminoglycan model polymers

Article abstract of DOI:10.1246/bcsj.20100094

We synthesized a novel glycopolymer library with 6-sulfo-GlcNAc and glucuronicacid(GlcA) based on the structure of glycosaminoglycans. The molecular weights of the polymers were controlled via living radical polymerization. The interactions of Aβ(1-40)ith glycopolymers were analyzed by inhibition activity of protein aggregation using ThT fluorescence assay, atomic force microscopy observation, and CD spectra. The inhibition activity of Aβ was much affected by the sugar structure and molecular weight of the polymer. The glycopolymers carrying 6-sulfo-GlcNAc showed inhibition activity toward Aβ aggregate, and those with 6-suflo-GlcNAc and GlcA showed the strong inhibition activity. The glycopolymer libraries yielded valuable information about Aβ aggregate with glycosaminoglycans.

Full text of DOI:10.1246/bcsj.20100094

1004 Bull. Chem. Soc. Jpn. Vol. 83, No. 9, 1004–1009 (2010)
© 2010 The Chemical Society of Japan
BCSJ Award Article
Interaction Analyses of Amyloid ¢ Peptide (1-40) with
Glycosaminoglycan Model Polymers
Yoshiko Miura*,³ and Hikaru Mizuno
School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi 923-1292
Received April 2, 2010; E-mail: miuray@chem-eng.kyushu-u.ac.jp
We synthesized a novel glycopolymer library with 6-sulfo-GlcNAc and glucuronic acid (GlcA) based on
the structure of glycosaminoglycans. The molecular weights of the polymers were controlled via living radical
polymerization. The interactions of A¢(1-40) with glycopolymers were analyzed by inhibition activity of protein
aggregation using ThT fluorescence assay, atomic force microscopy observation, and CD spectra. The inhibition activity
of A¢ was much affected by the sugar structure and molecular weight of the polymer. The glycopolymers carrying
6-sulfo-GlcNAc showed inhibition activity toward A¢ aggregate, and those with 6-suflo-GlcNAc and GlcA showed
the strong inhibition activity. The glycopolymer libraries yielded valuable information about A¢ aggregate with
glycosaminoglycans.
Alzheimer’s disease (AD) is a serious form of dementia.1
The defining features of AD are amyloid deposits, neuro-
fibrillary tangles, and selective neuronal loss. The major
component of the amyloid deposits is a 39-43 residue
peptide, amyloid ¢ (A¢).2 Since AD is strongly related to
the amyloidosis of A¢, it is important to clarify the mechanism
of formation and inhibition of A¢ aggregates.
It has been reported that the glycosaminoglycans (GAGs) on
cell surfaces play important roles in aggregation of A¢.3 GAGs
interact with A¢ to act as a scaffold for the assembly of fibrils,
and the amount of GAGs in the brain tissue from victims of AD
is increased. At the same time, oligomers of GAGs have been
reported to inhibit A¢ aggregate.4,5 Consequently, the GAGs-
A¢ interaction is a key factor for control of A¢ aggregate, and
GAGs-based compounds are potential medicines for AD. It
is thus necessary to analyze in detail the mechanism of the
GAGs-A¢ interaction. So far, McLaurin et al. reported the
effect of GAGs such as heparin, heparan, and chondroitin
sulfate on fibril formation.6 It was confirmed that the GAGs
affect the fibril formation of A¢, but the detailed interaction
including the role of saccharides was unclear.
too complex to allow the details of their interaction with
A¢ to be elucidated directly, and an ingenious method to
analyze the interaction is needed.7,8 We have reported use of
sulfonated glycopolymers as mimic polymers of GAGs, to
investigate the GAGs-A¢ interaction.9 The advantage of
glycopolymers is facile preparation, so that the effects of
saccharide structure and polymer molecular weight can be
easily investigated.
In the present study we synthesized glycopolymer libraries
with 6-sulfo-¢-GlcNAc and glucuronic acid (GlcA), based on
the GAGs structure (Figure 1). The polymers with various
molecular weights were also synthesized via reversible
addition-fragmentation chain transfer (RAFT) living radical
polymerization.10 The influence of the polymers on A¢(1-40)
aggregate was studied in detail by ThT fluorescence assay,
morphology observation, and conformation measurements.
A¢(1-40) was selected in order to analyze the detailed
inhibition effect and kinetics.
Experimental
Materials. The following reagents were used as received:
amyloid ¢-protein (A¢(1-40)) (Bachem AG, Switzerland),
2,2¤-azobis(2-amidinopropane)dihydrochloride (AAPD) (Wako
Chemical, Osaka, Japan), (thiobenzoyl)thioglycolic acid, hya-
luronic acid from rooster comb (Sigma-Aldrich, Louisiana,
MO, USA), heparin sodium salt from hog intestine, hexafluoro-
2-propanol (HFIP), p-nitrophenyl-D-glucose, Pd/C, and thio-
flavin T (ThT) (TCI, Tokyo, Japan).
The GAGs are composed of various disaccharide moieties
of uronic acid and glucosamine residues, and have highly
complex chemical structures due to the diversity of the
saccharide component by epimerization, sulfonation, and high
molecular weight. The chemical structures of the GAGs are
³ Present address: Department of Chemical Engineering, Faculty
of Engineering, Kyushu University, 744 Motooka, Nishi-ku,
Fukuoka 819-0395
Characterization.
recorded in D2O at room temperature with a Varian Gemini-
1H NMR (300 MHz) spectra were
Published on the web August 12, 2010; doi:10.1246/bcsj.20100094

Y. Miura et al.
Bull. Chem. Soc. Jpn. Vol. 83, No. 9 (2010) 1005
Figure 1. Chemical structures and molecular weights (Mn) of glycopolymers used in this study.
300 spectrometer, and mass spectra were obtained with an
ESI-MS LCQ-DECA XP spectrometer (Thermo Scientific,
Waltham, MA, USA). Gel permeation chromatography (GPC)
was conducted with a JASCO 800 high-performance liquid
chromatography instrument on a Shodex SB-804HQ column
with PBS as eluent, using a pullulan molecular weight
standard. Fluorescence intensity was measured with an LS55
instrument (Perkin-Elmer, Waltham, MA, USA), CD spectra
were recorded using a JASCO J-720 spectrometer (JASCO,
Tokyo, Japan), and an SPA400 instrument (Seiko Instruments
Inc., Tokyo) with 40 N cantilever was used for AFM.
nM ! Pn ðnucleation process, knÞ
M þ Pn ! Pnþ1 ðelongation process, keÞ
ð1Þ
where M and Pn denote monomeric and polymeric peptide,
respectively. The kinetic constants obtained were kn and ke for
nucleation and elongation of amyloid fibrils.
ThT data were analyzed in terms of a nucleation dependent
polymerization mechanism. This approach considers amyloid
fibril formation as an autocatalytic process with nucleation
followed by an elongation reaction, with their respective
kinetic constants kn and ke. Experimental data can be fitted to
such a model using eq 2
Glycopolymers.
p-(N-Acrylamido)phenyl pyranosides
were synthesized via hydrogenation of p-nitrophenyl pyrano-
sides, and subsequent treatment with acryloyl chloride.11,12
Details of the syntheses are given in the Supporting Informa-
tion. Polymerization was conducted via living radical polymer-
ization using the radical initiator AAPD with (thiobenzoyl)thio-
glycolic acid as a RAFT reagent.
µfexp½ð1 þ µÞktꢀ ꢁ 1g
f ¼
ð2Þ
f1 þ µ exp½ð1 þ µÞktꢀg
where f is the fraction of the fibrillar form; k = kea, where
a is the initial peptide concentration, and µ = kn/k. To fit
the experimental data to eq 2, fluorescence was converted
to fraction of fibril formation, with the condition f = 0 at
t = 0.
ThT Fluorescence Assays.13 A¢(1-40) was monomerized
¹1
in HFIP at 2.25 mg mL and dried under N2 at 0 °C, then
stored at ¹80 °C. ThT fluorescence assay was performed
for A¢(1-40) in 50 mM phosphate buffer with 100 mM
NaCl at pH 7.5. ThT (20 ¯M) was added to 100 ¯L of each
A¢ (23 ¯M) solution in a 96-microwell plate at 37 °C, and the
mixtures incubated with shaking at 400 rpm (Incubator FMS,
EYELA, Tokyo). The fluorescence intensity was measured
with excitation at 450 nm and emission at 485 nm. The time-
course of fluorescence was determined via measurements at 1 h
intervals.
AFM Measurements. A¢(1-40) solution (100 ¯L, 23 ¯M)
was incubated for 48 h in the presence or absence of
glycopolymers in phosphate buffer (50 mM phosphate buffer,
100 mM NaCl, pH 7.5). An aliquot of the sample solution
(5 ¯L) was placed on freshly cleaved mica, rinsed with
deionized water (100 ¯L © 5) and dried. The resultant sample
was scanned by D-AFM.
CD Spectra. A¢(1-40) was monomerized according to the
procedure used in the ThT assay. 200 ¯L of A¢ solution
(46 ¯M) was incubated at 37 °C in a 96 microwell plate with
shaking (400 rpm) for 9 days, then used as seed solution.15
Kinetic Analyses of ThT Fluorescence Data.
ThT
fluorescence data were analyzed by the kinetic scheme14

1006 Bull. Chem. Soc. Jpn. Vol. 83, No. 9 (2010) BCSJ AWARD ARTICLE
Table 1. Polymerization of Poly(acrylamide/6-sulfo-¢-GlcNAc/GlcA)
Concentration of
RAFT reagent
/mol %
a)
a)
Mn
Mw
Conv. Sugar contentb)
No.
Mw/Mn
6S-GlcNAc:GlcA
¹1
¹1
/g mol
/g mol
/%
/%
3-1
3-2
3-3
4-1
4-2
4-3
5-1
5-2
5-3
2.1 © 105
4.4 © 104
7.8 © 103
7.3 © 104
3.7 © 104
9.6 © 103
1.0 © 105
3.7 © 104
7.6 © 103
2.1 © 105
6.1 © 104
1.0 © 104
1.2 © 105
6.7 © 104
1.2 © 104
1.4 © 105
6.8 © 104
1.0 © 104
1.0
1.4
1.3
1.7
1.8
1.3
1.3
1.8
1.4
1
67
61
15
81
77
16
81
82
16
9.3
9.6
12.4
12.5
9.2
13.7
10.0
10.3
17.4
1:0
1:0
1:0
0:1
0:1
0:1
1:0.75
1:0.72
1:0.89
0.10
0.50
1.0
0.10
0.50
1.0
0.10
0.50
1.0
a) Relative to pullulan standard. b) By H NMR.
1.0 ¯L of seed solution was added to the A¢ solution (199 ¯L),
which was prepared following the ThT assay solution proce-
dure. The final concentration was 46 ¯M by UV absorption
(280 nm). The solution was incubated for 48 h, and CD spectra
were recorded at room temperature using a 2 mm cuvette.
Spectra were obtained from 260 to 190 nm at 50 nm min¹1 scan
speed, and 16 spectra were accumulated for each sample.
Kinetic Analyses. ThT fluorescence traces were kinetically
fitted in terms of amyloid nucleation (kn) and elongation (ke)
rate constants (Table 2). The glycopolymers with 6-sulfo-
GlcNAc (3-1, 3-2, and 3-3) showed smaller kn and larger ke,
by comparison with the ThT curve without additives. The
glycopolymer with smaller molecular weight (3-3) showed
smaller kn, and larger ke, hence inhibition of nucleation and
acceleration of amyloid fibril elongation. In the case of
glycopolymers with GlcA (4-1, 4-2, and 4-3), somewhat larger
kn and smaller ke were found. The terpolymers with both
6-sulfo-GlcNAc and GlcA (5-1, 5-2, and 5-3) showed the
smallest kn and modest ke values, signifying inhibition of
amyloid nucleation and fibril formation. These results indicated
that the saccharide structure of GAGs was strongly correlated
with amyloidosis. The kinetic analyses suggested that the
terpolymer with 6-sulfo-GlcNAc and GlcA was effective for
A¢ aggregate. The molecular weight of the polymers also had
an effect on the aggregation behavior of A¢; low molecular
weight glycopolymers exhibited smaller kn.
Those results indicated that the binding of sulfonated
GlcNAc to A¢ inhibited nucleation but contributed to fibril
formation. The binding of glycopolymers to A¢ was consid-
ered to be occurred via an electrostatic interaction between the
sulfonated groups of the 6-sulfo-GlcNAc and the basic residue
in the HHQK domain.16,17 The glycopolymers without sulfo-
nated group did not inhibit the aggregation of A¢ in this
experiment and our previous research.9 The binding of A¢ to
sulfonated glycopolymer inhibited the binding to other A¢,
which inhibited nucleation and amyloidosis. At the same time,
the sulfonated GlcNAc contributed to fibril formation, which
was consistent with the previous report that the addition of
GAGs induces the fibril formation of A¢ due to the scaffold
effect for fibril formation.6 Since the sugar contents of the
glycopolymers were modest, the glycopolymers did not act
as a scaffold for the fibrils assembly and did not induce the
extensive aggregation.
Results and Discussion
Syntheses of Glycopolymers.11,12
The syntheses of
glycopolymers were conducted via living radical polymeriza-
tion (Figure 1 and Table 1). The sugar ratio of the polymer was
fixed at about 10%, because glycopolymers with modest sugar
ratio have been found to show stronger inhibitory effects
toward A¢(1-42) aggregate.9 The molecular weights of the
glycopolymers were of the order 103, 104, and 105 g mol¹1 with
different RAFT reagent ratios. We synthesized the glycopoly-
mers of 6-sulfo-GlcNAc and glucuronic acid (GlcA), and also
prepared the terpolymer with 6-sulfo-GlcNAc and GlcA as a
glycosaminoglycan mimic polymer.
ThT Fluorescence Assay. Aggregation of A¢(1-40) was
monitored using ThT fluorescence intensity with addition of
glycopolymers (Figure 2). A¢ without polymer additives
showed a characteristic sigmoidal curve, indicating aggregation
with increasing incubation time. The addition of specific
glycopolymers changed the time course curve of fluorescence
intensity. While addition of the monomer of 6-sulfo-GlcNAc
(1) was not effective, the addition of glycopolymers with
6-sulfo-GlcNAc (3-1, 3-2, and 3-3) changed the ThT time
course curve. The addition of glycopolymers with 6-sulfo-
GlcNAc extended the lag time (Supporting Information), and
reduced the final fluorescence intensity. The polymer with
lower molecular weight (3-3) both reduced the fluorescence
intensity and extended the lag time to a greater extent than the
polymer with higher molecular weight (3-1). The addition of
glycopolymer with GlcA (4-1, 4-2, and 4-3) did not result in
significant changes in the ThT intensity vs. time curve; the lag
time was almost the same as that without additives. By contrast,
the glyco-terpolymers with 6-sulfo-GlcNAc and GlcA (5-1,
5-2, and 5-3) induced drastic changes in the ThT curve; the
fluorescence intensity was decreased by 70% and the lag time
increased. In particular, the terpolymer of 5-3 was the best
inhibitor of all the glycopolymers.
GlcA residue showed weak interaction with A¢, and a little
acceleration of nucleation. The acidity of GlcA was too weak to
interact with basic amino acid residues, and so the glycopoly-
mer with GlcA was not effective inhibitor of A¢ aggregate.
Rather, the glycopolymer with GlcA might provide a nuclea-
tion field for A¢. On the other hand, the terpolymers (5-1, 5-2,
and 5-3) were the most suitable for the inhibitory effect. It is

Y. Miura et al.
Bull. Chem. Soc. Jpn. Vol. 83, No. 9 (2010) 1007
Table 2. Nucleation and Elongation Rate Constants
Calculated by Fitting ThT Data
¹1
¹1
Sample
kn/s
ke/L mol¹1 s
¹6
A¢ (control)
1
3-1
3-2
3-3
2
4-1
4-2
4-3
5-1
5-2
5-3
1.3 © 10
1.4 © 10
7.3 © 10
2.5 © 10
5.1 © 10
3.4 © 10
4.2 © 10
2.5 © 10
6.7 © 10
1.3 © 10
6.7 © 10
6.8 © 10
3.1 © 10
1.5 © 10
3.4
3.7
6.6
5.9
7.9
3.0
2.5
4.2
2.5
4.3
3.4
3.1
3.7
3.4
¹6
¹9
¹8
¹10
¹6
¹6
¹6
¹6
¹6
¹7
¹7
¹6
¹6
Heparin
Hyaluronic acid
weak compared to 6-sulfo-GlcNAc based on the ThT results of
3-3 and 4-3. But the cooperative binding to 6-sulfo-GlcNAc
and GlcA is advantageous to the A¢ binding.19 Thus, the
glycopolymers with 6-sulfo-GlcNAc and GlcA (5-1, 5-2, and
5-3) showed a better inhibition effect on A¢ aggregate than
those with 6-sulfo-GlcNAc (3-1, 3-2, and 3-3).
The molecular weight dependence was significant, and the
low molecular weight polymers showed the stronger inhibition
effects. It has also been reported that the low molecular weight
heparin inhibited A¢ aggregate.4,5 Molecular weight changes
affect the physical properties of the polymers such as
mobility,20,21 and the low molecular weight polymers had
better mobility. It has been reported that glycopolymer with
better mobility showed better binding properties to the target
protein,22 and so the greater mobility could contribute to
the better binding. In addition, we fixed the concentration of
sugars in the experiments, and the number of the molecules
was different. That is, the low molecular weight of polymers
had a larger number of molecules than did the high molecular
weight polymers, though the sugar concentration was the same.
The difference in number of molecules could contribute to
binding by the entropy effect, which gives better binding of
low molecular weight polymers.23 Detailed analyses of the
molecular weight effect are still under investigation, but the
glycopolymers with smaller molecular weights definitely had
better affinities to A¢, resulting in inhibition of nucleation.
Since the monomer did not show the inhibitory effect, the
multivalent sugar compounds with low molecular weight were
the best design for inhibition of A¢ aggregate.
Figure 2. Time course of fibril formation at pH 7.5 and
37 °C with 400 rpm shaking monitored by ThT fluores-
cence. The concentrations of A¢ and sugar were 23
and 200 ¯M, respectively. The sugar additives were (a)
poly(acrylamide/6-sulfo-GlcNAc), (b) poly(acrylamide/
GlcA), and (c) poly(acrylamide/GlcA/6-sulfo-GlcNAc).
AFM Measurements.
The morphologies of A¢ with
various additives were investigated by AFM; representative
data are shown in Figure 3. The A¢ aggregates without
additives formed amyloid fibrils with length 1-3.5 ¯m, width
160-230 nm, and height 15-45 nm (Figure 3a). The glyco-
polymers with 6-sulfo-GlcNAc (3-1, -2, -3 and 5-1, -2, -3)
changed the morphology to smaller amyloids. In addition, the
morphology change was clearly dependant on the molecular
weight of the glycopolymer additives: the additives with
smaller molecular weight showed better inhibitory effects on
A¢ aggregate. For example, the A¢ aggregates with 3-1 were
0.48-2.8 ¯m long, 80-180 nm wide, and 6-35 nm high, and
noteworthy that the polymers having the most suitable mimic
structure with uronic acid and sulfonated GlcNAc showed the
best inhibitory effects.
The glycosaminoglycans are composed of uronic acid and
sulfonated glucosamine residues.18 Consequently, the proteins
might have affinity not only to the sulfonated glucosamine but
also uronic acid portion. The binding to GlcA is expected to be

1008 Bull. Chem. Soc. Jpn. Vol. 83, No. 9 (2010) BCSJ AWARD ARTICLE
Figure 3. AFM images of the aggregates of A¢(1-40).
Amyloid fibrils were obtained by incubation of A¢
(23 ¯M) at pH 7.5 and 37 °C with 400 rpm shaking for
48 h. The images were (a) without glycopolymer, (b) in the
presence of 3-3 (200 ¯M), (c) in the presence of 4-3
(200 ¯M), and (d) in the presence of 5-3 (200 ¯M).
those with 3-3 had length 0.19-2.0 ¯m, width 110-180 nm, and
height 1-8 nm (Figure 3b). Glycopolymers with both 6-sulfo-
GlcNAc and GlcA (5-1, 5-2, and 5-3) changed the morphol-
ogies to the large extent. A¢ with 5-3 strikingly reduced the
size of the amyloids to 0.10-1.7 ¯m length, 80-120 nm width,
and 1.5-4.0 nm height (Figure 3d). On the other hand, the
glycopolymers without 6-sulfo-GlcNAc (with only GlcA, 4-1,
4-2, and 4-3) did not show the changes in morphology that
Figure 4. CD spectra of A¢(1-40). The A¢ solution was
were visible by AFM observation (Figure 3c). Those observa-
tions were consistent with the results of the ThT fluorescence
assay.
prepared by the incubation of A¢ (46 ¯M) at pH 7.5 and
37 °C with 400 rpm shaking for 48 h. The CD spectra were
(a) in the presence of glycopolymers of 3-3, 4-3, and 5-3 at
CD Spectra Measurement. The conformation of A¢ was
determined with glycopolymers (Figure 4).24 A¢ without
additives showed a negative Cotton effect around 220 nm,
suggesting a ¢-sheet structure. Addition of glycopolymers
induced specific conformations in A¢ (Figure 4a). Glyco-
polymers with 6-sulfo-GlcNAc (3-1, 3-2, and 3-3) gave a
¢-sheet structure for which the intensity of the Cotton effect
was smaller than for the control sample. In the case of ter-
glycopolymers (5-1, 5-2, and 5-3), the spectra showed broad
negative Cotton effects with weaker intensity.
Interestingly, the glycopolymers with GlcA (4-1, 4-2, and
4-3) induced a different conformation: the CD spectra showed a
negative Cotton effect at 208 and 218 nm, suggesting a helical
structure. We also measured the CD spectra of A¢ in ethanol
solution to induce the helical structure due to the hydropho-
bicity,24 and the intensity of the Cotton effect around 208 nm
was almost the same as that with 4-3. The clear difference in
400 ¯M, and (b) in the presence of polysaccharide of
¹1
hyaluronic acid and heparin at 1.0 mg mL
.
conformation showed that the interactions of A¢ with GAGs
affected amyloidosis and induced specific conformations.
We examined the conformation of A¢ with addition of
natural GAGs of heparin (possessing 6-sulfo-GlcNAc) and
hyaluronic acid (possessing GlcA). The addition of real GAGs
also changed the conformation of A¢ (Figure 4b). Heparin
induced a negative Cotton effect at 218 nm, hence gave rise to a
¢-sheet structure, and the addition of hyaluronic acid induced
a broad negative Cotton effect at 208 nm, suggesting a different
conformation from ¢-sheet. The CD spectra with GAGs
reflected those with model glycopolymers. Comparing the
sulfonated GAGs (such as heparin and heparan), attention was
not paid to the role of uronic acid and hyaluronic acid due to
the weak interaction. If the polyvalent uronic acid or hyaluronic

Y. Miura et al.
Bull. Chem. Soc. Jpn. Vol. 83, No. 9 (2010) 1009
acid can operate as a molecular chaperon in amyloidosis,25 the
molecules could be useful bioactive compounds.
3
1030.
4
J. R. Bishop, M. Schuksz, J. D. Esko, Nature 2007, 446,
M. Walzer, S. Lorenz, M. Hejna, J. Fareed, I. Hanin, U.
The correlation between secondary structure by CD and
aggregation properties were contrary to the previous reports. It
has been reported that the amyloid fibrils are composed of ¢-
sheet rich proteins. However, in our results with glycopoly-
mers, the A¢ with ¢-sheet structure in the presence of 3-3 and
5-3 showed less aggregation properties with ThT and AFM.
The A¢ with helical structure in the presence of 4-3 showed
strong aggregation properties by ThT.
It has been suggested that the conformation of A¢ was
affected by the HHQK region.16,17,26 It is possible that the
binding of 6-sulfo-GlcNAc to the HHQK domain changes the
conformation of A¢ into ¢-sheet. However, at the same time
the strong binding of glycopolymer to A¢ inhibited the
aggregation between each A¢ peptide. In this experiment, the
strong binding of A¢ was more important than secondary
structure in inhibition of A¢ aggregate. Hence, in the presence
of glycopolymer, A¢ with ¢-sheet like structure showed
weaker aggregative properties.
Cornelli, J. M. Lee, Eur. J. Pharmacol. 2002, 445, 211.
5
6
H. Zhu, J. Yu, M. S. Kindy, Mol. Med. 2001, 7, 517.
J. McLaurin, T. Franklin, X. Zhang, J. Deng, P. E. Fraser,
Eur. J. Biochem. 1999, 266, 1101.
Y. Suda, A. Arano, Y. Fukui, S. Koshida, M. Wakao, T.
7
Nishimura, S. Kusumoto, M. Sobel, Bioconjugate Chem. 2006, 17,
1125.
8
M. Rawat, C. I. Gama, J. B. Matson, L. C. Hsieh-Wilson,
J. Am. Chem. Soc. 2008, 130, 2959.
Y. Miura, K. Yasuda, K. Yamamoto, M. Koike, Y. Nishida,
9
K. Kobayashi, Biomacromolecules 2007, 8, 2129.
10 G. Moad, E. Rizzardo, S. H. Thang, Acc. Chem. Res. 2008,
41, 1133.
11 Organic Chemistry of Sugars, ed. by D. E. Levy, P. Fugedi,
Marcel Dekker Inc., New York, 2005.
12 K. Sasaki, Y. Nishida, M. Kambara, H. Uzawa, T.
Takahashi, T. Suzuki, Y. Suzuki, K. Kobayashi, Bioorg. Med.
Chem. 2004, 12, 1367.
13 N. Tanaka, R. Tanaka, M. Tokuhara, S. Kunugi, Y.-F. Lee,
D. Hamada, Biochemistry 2008, 47, 2961.
Conclusion
14 R. Sabaté, M. Gallardo, J. Estelrich, Biopolymers 2003, 71,
190.
15 M. P. Williamson, Y. Suzuki, N. T. Bourne, T. Asakura,
Biochem. J. 2006, 397, 483.
16 D. Giulian, L. J. Haverkamp, J. Yu, W. Karshin, D. Tom, J.
Li, A. Kazanskaia, J. Kirkpatrick, A. E. Roher, J. Biol. Chem.
1998, 273, 29719.
17 A. Würger, Phys. Rev. Lett. 2009, 102, 078302.
18 a) S. Koshida, Y. Suda, M. Sobel, J. Ormsby, S. Kusumoto,
Bioorg. Med. Chem. Lett. 1999, 9, 3127. b) Y. Suda, D. Marques,
J. C. Kermode, S. Kusumoto, M. Sobel, Thromb. Res. 1993, 69,
501.
We investigated the syntheses and biological properties of
GAGs mimic polymers for A¢. The addition of GAGs mimic
polymers produced specific properties based on the pendant
saccharide structures. An appropriate glycopolymer with
saccharide structure and suitable molecular weight can control
the amyloidosis and conformation of A¢. These approaches
provide information on the function of GAGs in relation to
Alzheimer’s disease. The detailed functionalities of GAGs in
AD are still unclear, but our experiments with glycopolymers
could reveal partial functionalities.
This work was supported by a Grant-in-Aid for Young
Scientists (B) (No. 20750088). The authors are grateful to Prof.
Naoki Tanaka (Kyoto Institute of Technology) for help of ThT
measurements.
19 V. Novokhatny, F. Schwarz, D. Atha, K. Ingham, J. Mol.
Biol. 1992, 227, 1182.
20 T. Radeva, I. Petkanchin, J. Colloid Interface Sci. 1999,
220, 112.
21 L. L. Burshtein, V. P. Malinovskaya, T. P. Stepanova,
Polym. Sci. U.S.S.R. 1978, 20, 2475.
Supporting Information
22 T. Ooya, M. Eguchi, N. Yui, J. Am. Chem. Soc. 2003, 125,
13016.
23 A. Muramoto, Polymer 1982, 23, 1311.
24 M. D. Kirkitadze, M. M. Condron, D. B. Teplow, J. Mol.
Biol. 2001, 312, 1103.
The synthetic procedure of polymers, AFM, CD data, and
the schematic description of ThT assay. These materials are
available free of charge on the web at http://www.csj.jp/
journals/bcsj/.
25 Y. Nomura, M. Ikeda, N. Yamaguchi, Y. Aoyama, K.
Akiyoshi, FEBS Lett. 2003, 553, 271.
References
1
2
M. P. Mattson, Nature 2004, 430, 631.
D. J. Selkoe, Annu. Rev. Neurosci. 1994, 17, 489.
26 T. Ban, M. Hoshino, S. Takahashi, D. Hamada, K.
Hasegawa, H. Naiki, Y. Goto, J. Mol. Biol. 2004, 344, 757.