Self-Assembling Property of Peptide-Surfactant with Diacetylene Unit
Tomoyuki K
OGA,
*Minoru U
MEDA*and Nobuyuki H
IGASHI*(Received February 27, 2007)
In this study, we prepared a novel peptide-surfactant 1, in which the (Leu)4(Lys)8(Leu)4 was conjugated with the hydrophobic surfactant tail containing the diacetylene unit, and its self-assembling property was examined in water. The secondary structure of peptide1 was examined by means of CD spectroscopy in water at various pHs. The peptide 1 formed E-sheet structure at above pH 4, but existed in random-coil structure at low pH region (< pH 4). Interestingly, however, the conformation of 1 strongly depended on incubation time at pH 3.9, and as a result, structural transition from random-coil to E-sheet was observed within 100 hours. In parallel with such conformational change, the peptide 1 self-assembled into nanofiber structure with ca. 20 nm height. Considering the molecular length of the peptide 1 in E-sheet form (8.7 nm), it seems that this nanofiber is rod-like micelle which consists of hydrophobic surfactant core and hydrophilic peptide shell. UV-irradiation to this nanofiber did not cause polymerization of diacetylene group, probably due to unfavorable packing for topochemical polymerization.
Key words: Peptide-surfactant, Self-assembly, Diacetylene, Nanofiber, E-sheet 䉨䊷䊪䊷䊄: ࡍࡊ࠴࠼⢽⾰, ⥄Ꮖ㓸ว, ࠫࠕ࠴ࡦ, ࠽ࡁࡈࠔࠗࡃ,E-ࠪ࠻
ࠫࠕ࠴ࡦၮࠍߔࠆਔⷫᇦᕈࡍࡊ࠴࠼⢽⾰ߩ⥄Ꮖ⚵❱ൻ
ฎ⾐ ᥓਯ᪢↰ ⓛ᧲ ାⴕ
ߪߓߦ
ㄭᐕ㧘࠽ࡁࠬࠤ࡞ߩᓸ⚦ߥ᭴ㅧࠍᒻᚑߔࠆᣇ ᴺߣߒߡ㧘ಽሶߩ⥄Ꮖ⚵❱ൻࠍ↪ߔࠆࡏ࠻ࡓࠕ࠶
ࡊ⊛ߥᚻᴺߦᵈ⋡߇㓸߹ߞߡࠆ㧚․ߦ㧘ಽሶ⚛᧚ ߣߒߡੱᎿࡍࡊ࠴࠼ࠍ↪ߚ⥄Ꮖ⚵❱ൻߦ㑐ߔࠆ
⎇ⓥߪ㧘࠲ࡦࡄࠢ⾰ߩ┙᭴ㅧࡕ࠺࡞ߣߒߡߛߌߢ ߥߊ㧘ᣂߚߥᯏ⢻ᕈ࠽ࡁ᧚ᢱࠍഃߔࠆߢ㕖Ᏹߦ
↪ߢࠅᄙߊߩᵈ⋡ࠍ㓸ߡࠆ
1-10)㧚ߎߩ⥄Ꮖ
⚵❱ൻߪ᳓⚛⚿ว߿⇹᳓ᕈ⋧↪㧘㕒㔚⋧↪
ߥߤߩ㕖⚿วᕈߩ⋧↪ࠍᏁߺߦ↪ߒߡ ⴕࠊࠇࠆ㧚ᚒޘߩ⎇ⓥࠣ࡞ࡊߦ߅ߡ߽ߎࠇ߹ߢ ߦ㧘⇹᳓ᕈࠕࡒࡁ㉄ߩࡠࠗࠪࡦ (L) ߅ࠃ߮ⷫ᳓ᕈࠕࡒ ࡁ㉄ߩࠪࡦ (K) ߆ࠄߥࠆන⚐ߥਔⷫᇦᕈࡍࡊ࠴࠼
߇ࠕࡒࡁ㉄㈩߿ᄖㇱ pH ߥߤߦࠃࠅ㧘
D-߳࠶ࠢ
ࠬ᭴ㅧߦၮߠߚ࠽ࡁࡊ࠻߿࠽ࡁ☸ሶ㧘
E-ࠪ
࠻᭴ㅧߦၮߠߚ࠽ࡁࡈࠔࠗࡃߥߤ᭽ޘߥ࠽
ࡁ⚵❱ߦ⥄Ꮖ⚵❱ൻߔࠆߎߣࠍߒߡࠆ
9,10)㧚 ߒ߆ߒ㧘㕖⚿วᕈߩ⋧↪ߢᒻᚑߐࠇߚ࠽ࡁ
⚵❱ߪ㧘ᾲ⊛㧘ൻቇ⊛ߦਇቯߢࠆߎߣ߇ᄙߊ㧘 Ꮏቇ᧚ᢱߣߒߡ↪ߔࠆߎߣࠍᜰะߒߚ႐วߩ࠺
ࡔ࠶࠻ߣߥࠆ㧚
ᧄ⎇ⓥߢߪ㧘ࡍࡊ࠴࠼࠽ࡁ⚵❱ߩ᭴ㅧቯൻ ߥࠄ߮ߦᯏ⢻ൻࠍ࿑ࠆߎߣࠍ⋡⊛ߣߒߡ㧘ࠫࠕ࠴
ࡦၮࠍ⥄Ꮖ㓸วᕈࡍࡊ࠴࠼ߦ⚵ߺㄟߎߣࠍ⠨
߃ߚ㧚ࠫࠕ࠴ࡦߪశߥߤߩᾖߦࠃࠅ㧘 1,4- ઃ ടᔕ߇⺃ߐࠇࡐࠫࠕ࠴ࡦࠍ↢ᚑߔࠆ
11)㧚 ߎߩᔕߪ
,ࡕࡁࡑಽሶߩ㈩⁁ᘒ߿ಝ㓸⁁ᘒ ߇࿕⋧㊀วߩᔕᕈߣ↢ᚑߔࠆࡐࡑߩ᭴ㅧ ࠍᡰ㈩ߔࠆ࠻ࡐࠤࡒࠞ࡞㊀วߢࠆ㧚↢ᚑߔࠆࡐ
ࠫࠕ࠴ࡦߪߘߩലᓎ㐳ߩ㆑ߦࠃߞ
*Department of Molecular Science & Technology, Faculty of Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan, Tel :+81-774-65-6621, -6622, Fax:+81-774-65-6844, E-mail: [email protected], [email protected]
ߡ㕍⋧㧘⿒⋧ߣߞߚ⇣ߥࠆ⦡⋧12)ࠍ␜ߔߛߌߢ ߥߊ㧘᭽ޘߥᄖㇱೝỗߦᔕ╵ߒߡ⦡⋧ォ⒖ࠍߎߔ ߎߣ߽⍮ࠄࠇߡࠆ㧚ߎࠇ߹ߢߦ
LB
⤑13-14)߿᳇᳓⇇㕙නಽሶ⤑15-16)㧘
SAM
⤑17-18)㧘ࡌࠪࠢ࡞19)㧘࠽ࡁ࠴ࡘࡉ߅ࠃ߮࠽ࡁࡈࠔࠗࡃ20-23)ߥߤߩ᭽ޘߥ ಽሶ㓸ว♽ߦ߅ߡࠫࠕ࠴ࡦၮߩ࠻ࡐࠤࡒࠞ
࡞㊀ว߇ႎ๔ߐࠇߡ߅ࠅ㧘ᓧࠄࠇߚࡐࠫࠕ࠴
ࡦߩ⦡⋧ᄌൻࠍ↪ߒߚಽሶࡦࠨ╬߳ߩᔕ↪
߽ᬌ⸛ߐࠇߡࠆ㧚
ᧄ⺰ᢥߢߪ㧘⥄Ꮖ㓸วᕈࡍࡊ࠴࠼ߣߒߡ⇹᳓ᕈߩ ࡠࠗࠪࡦߣⷫ᳓ᕈߩࠪࡦࠍ࠻ࡉࡠ࠶ࠢဳߦ㈩
ߐߖߚਔⷫᇦᕈࡍࡊ࠴࠼
L
4K
8L
4ߦὶὐࠍᒰߡ㧘 ߘߩᧃ┵ߦ10,12-
ࡍࡦ࠲ࠦࠨࠫࠗࡦ㉄ࠍዉߒߚࠫࠕ࠴ࡦဳࡍࡊ࠴࠼⢽⾰
(1)
ࠍᣂⷙߦಽሶ⸳⸘วᚑߒߚ
(Figure 1)
㧚ߎࠇ߹ߢߩ⎇ⓥ߆ࠄL
4K
8L
4ߪ㧘ࠪࡦᱷၮߩ
pK
a ઃㄭߩpH
᧦ઙਅ(ca. 9.0)
ߦ߅ߡ D-ࡋ࠶ࠢࠬ᭴ㅧ߆ࠄ E-ࠪ࠻᭴ㅧߦ᭴ㅧォ⒖߇ߎࠅ㧘࠽ࡁࡈࠔࠗࡃࠍᒻᚑߔࠆߎߣ ߇ࠄ߆ߦߥߞߡࠆ10)㧚⋥ߥ⇹᳓ᕈߩࠫࠕ࠴
ࡦၮߩዉ߇㧘
L
4K
8L
4ࡍࡊ࠴࠼ߩ᳓ਛߢߩੑᰴ᭴ㅧ߿⥄Ꮖ㓸ว․ᕈߦ߅ࠃ߷ߔᓇ㗀ߦߟߡ⚦ߦ ᬌ⸛ߒߚ㧚߹ߚ㧘ᓧࠄࠇࠆࡍࡊ࠴࠼⥄Ꮖ㓸วਛߦ ߅ߡࠫࠕ࠴ࡦၮߩ࠻ࡐࠤࡒࠞ࡞㊀ว߇㆐ᚑ ߢ߈ࠇ߫㧘ߘߩ‛ℂ⊛ቯᕈࠍะߐߖࠆߎߣ߇ߢ ߈ࠆߛߌߢߥߊ㧘ᓎ᭴ㅧࠍߔࠆᣂߚߥᯏ⢻ᕈࡍ ࡊ࠴࠼᧚ᢱߣߒߡ᭽ޘߥಽ㊁ߢߩᔕ↪߽ᦼᓙߐࠇ ࠆ㧚
ታ㛎ᣇᴺ
⹜⮎
Fmoc-Leu-CLEAR (Cross-Linked Ethoxylate Acrylate Resin)-acid
᮸⢽, Fmoc-Leu
߅ࠃ߮Fmoc-Lys(Boc)
ߪࡍࡊ࠴࠼⎇ⓥᚲ␠߆ࠄ⾼ߒߚ㧚߹ߚ20%
ࡇࡍࠫࡦ
/N,N-
ࠫࡔ࠴࡞ࡎ࡞ࡓࠕࡒ࠼(DMF)
ṁᶧ,
1-ࡅ࠼ࡠࠠࠪࡌࡦ࠱࠻ࠕ࠱࡞
(HOBt)
ߪ࠽ࠞࠗ࠹ࠬࠢ␠
, 1-
ࡅ࠼ࡠࠠࠪ-7-
ࠕࠩࡌࡦ࠱࠻ࠕ࠱࡞
(HOAt)
ߪᷰㄝൻቇᎿᬺᩣᑼળ␠,
ࠫࠗ࠰ࡊࡠࡇ࡞ࠞ࡞ࡏࠫࠗࡒ࠼
(DIPCI)
ߪ᧲੩ൻᚑ␠ߩ߽ߩࠍ⾼ߒ㧘․ߦ♖ߔࠆߎߣߥߒߦ↪ߚ㧚߹ߚ
,
10,12-
ࡍࡦ࠲ࠦࠨࠫࠗࡦ㉄ߪࡦࠞࠬ࠲␠ߩ߽ߩࠍ⾼ߒ
,
㊀ว‛ࠍ㒰ߔࠆߚࠢࡠࡠࡎ࡞ࡓ ߦࠃࠆ♖ࠍⴕߞߚᓟߦ↪ߒߚ㧚ࠫࠕ࠴ࡦၮࠍߔࠆਔⷫᇦᕈࡍࡊ࠴࠼⢽
⾰ߩวᚑ
ࠫࠕ࠴ࡦဳࡍࡊ࠴࠼⢽⾰
(1)
ߪFmoc
࿕⋧วᚑᴺߦࠃࠅวᚑߒߚ㧚એਅߦߘߩ⚦ࠍ␜ߔ㧚
Fmoc-Leu-CLEAR
᮸⢽0.50 g (0.26 mmol/-NH
2ၮ)
ࠍDMF
ਛߢ৻᥅⤘Ảߐߖߚᓟ㧘ࠃߊᵞᵺߒߚ㧚ᰴߦ
, Fmoc
ၮࠍ㒰ߔࠆߚ20%
ࡇࡍࠫࡦ/DMF
ṁ ᶧ5 mL
ߢಣℂߒߚޕቢోߦFmoc
ၮࠍ㒰ߔࠆߚ
,
ߎߩᠲߪ3
ಽx2
࿁, 20
ಽx1
࿁ⴕߞߚ㧚ᰴߦ
DMF
ߢṁᶧ߇ਛᕈߦߥࠆ߹ߢᵞᵺߒ,
ߎߩ᮸⢽ࠍ
DMF 5 mL
ਛߢ㧘❗วߣߒߡDIPCI 0.10 g (0.78 mmol)
㧘⸅ᇦߣߒߡHOBt 0.11 g (0.78 mmol)
ࠍ↪ߡ㧘
Fmoc-
ࠕࡒࡁ㉄0.78 mmol (Fmoc-Leu: 0.28 g, Fmoc-Lys(BOC): 0.37 g)
ߣ2
ᤨ㑆ᔕߐߖߚ㧚ᔕᓟ㧘 ㆊߩ⹜⮎ࠍ㒰ߔࠆߚߦDMF
ߢ➅ࠅߒ(5 mL
x 3࿁)
ᵞᵺߒߚ㧚ห᭽ߦߒߡ, Fmoc
ၮߩ㒰Fmoc-
ࠕࡒࡁ㉄ߩ❗วࠍ⋡⊛ߩࡍࡊ࠴࠼㈩ߦߥࠆ߹ߢ➅ࠅߒⴕߞߚ㧚⋡⊛ߩࡍࡊ࠴࠼
(L
4K
8L
4)
ࠍ⺞ᓟ㧘Fmoc
ၮߩ㒰ࠍⴕߞߚᓟ㧘DMF 5 mL
ਛߦ߅ߡ10,12-
ࡍࡦ࠲ࠦࠨࠫࠗࡦ㉄0.29 g (0.78 mmol), DIPC 0.10 g (0.78 mmol), HOAt 0.11 g (0.78 mmol)
ࠍട߃ߡ3
ᣣ㑆ᔕߐߖ,
ࡍࡊ࠴࠼Nᧃ┵ߦ10,12-
ࡍ ࡦ ࠲ ࠦ ࠨ ࠫ ࠗ ࡦ ㉄ ࠍዉߒߚ㧚ߘߩᓟ, DMF 5 mL
ߣCH
2Cl
25 mL
ߢ➅ࠅߒᵞᵺߒߡ᮸⢽ࠍੇ῎ߐߖߚ㧚ੇ῎ᓟ
, TFA-
࠻ࠗ࠰ࡊࡠࡇ࡞ࠪFigure 1. Chemical structure of a novel peptide-surfactant with diacetylene unit (1) used as a building block for self-assembly, and its schematic illustration.
ࡦ (TIS)- ⫳⇐᳓ (9.5:0.25:0.25 v/v) 10 mL ਛߢ 2 ᤨ㑆 ᠣᜈߔࠆߎߣߢࡍࡊ࠴࠼ߩ᮸⢽߆ࠄߩಾࠅߒࠍ ⴕߞߚ㧚ዏ㧘ߎߩᠲߪ 2 ࿁ⴕߞߚ㧚ࠈᶧࠍ࿁ߒ TFA ࠍᷫỚ❗ߒߚᓟ㧘㕖ṁߦࠫࠛ࠴࡞ࠛ࠹࡞
ࠍ↪ߡౣᴉᲚࠍⴕ㧘ࠫࠛ࠴࡞ࠛ࠹࡞ߢ➅ࠅ
ߒᵞᵺߔࠆߎߣߢ㧘⊕⦡ߩ☳ᧃ (0.12 g) ࠍᓧߚ㧚᭴
ㅧߩ⏕ߪ
1H-NMR ࠬࡍࠢ࠻࡞ࠃࠅⴕ㧘ಽሶ㊂
ߩ⏕ߪ MALDI-TOFMS ࠬࡍࠢ࠻࡞ࠃࠅⴕߞߚ㧚
ߥ߅㧘ࡑ࠻࠶ࠢࠬߦߪ 2,5- ࠫࡅ࠼ࡠࠠࠪᕷ㚅㉄
ࠍ↪ߚ㧚
MALDI-MS: 2331 [M+Na]
+obsd./ 2328 [M+Na]
+Theory.
1
H-NMR (DMSO-d
6, TMS) 㧦 0.80 – 0.95 ppm ( 51H, CH
3), 1.10 – 1.75 ppm ( 104H, CH
2and CH
2CH(CH
3)
2), 2.05 – 2.20 ppm ( 6H, CH
2), 2.70 – 2.80 ppm ( 16H, CH
2CH
2NH
2), 4.00 – 4.80 ppm ( 16H, COCHNH ), 7.60 – 8.10 ppm ( 40H, CHNHCO and CH
2NH
3).
᷹ቯ
Cశੑ⦡ᕈ%&ࠬࡍࠢ࠻࡞
CD ࠬࡍࠢ࠻࡞ߩ᷹ቯߪᣣᧄಽశ␠ J-720 ߦࠃ ࠅⴕ㧘శ〝㐳 1 mm ߹ߚߪ 2 mm ߩ⍹⧷࡞ࠍ↪
ߡቶ᷷ߢⴕߞߚ㧚ዏ㧘ోߡߩࠨࡦࡊ࡞ߪએਅߩᣇ ᴺߢ⺞ߒߚ㧚߹ߕ
1ࠍ 2,2,2- ࠻ࡈ࡞ࠝࡠࠛ࠲ࡁ
࡞ (TFE) ߦṁ⸃ߐߖߡࠬ࠻࠶ࠢṁᶧߣߒ㧘ߎߩࠬ
࠻࠶ࠢṁᶧࠍ 5 mM ߩࠢࠛࡦ㉄ /Na
2HPO
4,Tris/HCl
߽ߒߊߪ Na
2HPO
4/NaOH ✭ⴣṁᶧߢᏗ㉼ߔࠆߎߣ ߢ⋡⊛ߩࠨࡦࡊ࡞ṁᶧ (40
PM) ࠍ⺞ߒߚ
(ᦨ⚳ TFE
㊂ 5 %) 㧚✭ⴣṁᶧߪ Milli-Q ᳓ࠪࠬ࠹ࡓ (Millipore
␠ ) ߦࠃࠅ♖ߐࠇߚ⚐᳓ (
U̓>18 Mǡ cm) ࠍ
↪ߡ⺞ߒߚޕዏ㧘Ⓧ▚࿁ᢙߪ 8 ࿁ߢ᷹ቯߒߚ㧚
Dේሶ㑆ജ㗼ᓸ㏜#(/᷹ቯAFM ⷰ ኤ ߪ ࡆ ࠦ ࠗ ࡦ ࠬ ࠷ ࡞ ࡔ ࡦ ࠷ ␠
Nanoscope Υ a ࠍ↪ߚ㧚ត㊎⒳ߪ MPP-1110 ࠞࡦ
࠴ࡃߩ㐳ߐ㧦 125
Pm ᝄᵄᢙ㧦 300 kHz ࡃ
ࡀቯᢙ㧦 40 N/m ត㊎ߩ㜞ߐ㧦 17.5
Pm ᦛ₸ඨᓘ㧦
<10 nm 㧘 Side Angle 㧦 15° (Micro), 18° (Macro), Front/Back angle (Front+Back)/2 angle 㧦 15° /25° /15°
(Micro) 㧘వ┵ᒻ⁁㧦྾ⷺ㍝ࠍ↪࠲࠶ࡇࡦࠣࡕ
࠼ߢࠬࠠࡖࡦㅦᐲ 1.0 Hz ߢ᷹ቯࠍⴕߞߚ㧚߹ߚ㧘 ࠨࡦࡊ࡞ߩ⺞ߪએਅߩ᭽ߦⴕߞߚ㧚 CD ࠬࡍࠢ
࠻࡞ߣห᭽ߩᣇᴺߢ⺞ߒߚࠨࡦࡊ࡞ṁᶧࠍࡑࠗ
ࠞ᧼ߦṢਅߒ㧘৻ቯᤨ㑆 (5-20 min) ࠗࡦࠠࡘࡌ
࠻ߔࠆߎߣߢࡍࡊ࠴࠼ࠍࡑࠗࠞߦๆ⌕ߐߖߚ㧚
ᰴߦࠈ⚕ࠍ↪ߡㆊߥṁᶧࠍ㒰ߒߚᓟ㧘ੇ῎ߐ ߖࠆߎߣߢࠨࡦࡊ࡞ࠍ⺞ߒߚ㧚
Eశ㊀ว
᳓ṁᶧਛߢߩశ㊀วㆊ⒟ߪ㧘ࠗࡦࠠࡘࡌ࠲ౝ
ࠍ 5 ͠ߢ৻ቯߣߜ
,ૐ᳓㌁Ἦࠍ↪ߡ 30 cm ߩ〒㔌߆ࠄశᾖࠍⴕ
,ፉᵤᚲ UV 2100 ࠍ
↪ߡ 2 mm ߩ⍹⧷࡞ਛߢㅊ〔ߒߚ㧚
⚿ᨐ߅ࠃ߮⠨ኤ
ࠫࠕ࠴ࡦၮࠍߔࠆਔⷫᇦᕈࡍࡊ࠴࠼⢽
⾰ߩಽሶ⸳⸘ߣวᚑ
ߎࠇ߹ߢߦ㧘ੱᎿࡍࡊ࠴࠼ߩ᳓ਛߢߩ⥄Ꮖ⚵❱ൻ
ᓮࠍ⋡⊛ߣߒߡ㧘⇹᳓ᕈߩࡠࠗࠪࡦ (L) ߣⷫ᳓ᕈߩ
ࠪࡦ (K) ࠍ᭽ޘߦ⚵ߺวࠊߖߚਔⷫᇦᕈࡍࡊ࠴࠼
ࠍวᚑߒ㧘ߘߩ⥄Ꮖ㓸ว․ᕈࠍᬌ⸛ߒߡ߈ߚ㧚
ᧄ⎇ⓥߢߪ㧘ߘߩㆊ⒟ߦ߅ߡߒߚ࠽ࡁࡈࠔࠗ
ࡃᒻᚑࡍࡊ࠴࠼ (L
4K
8L
4) ߦ⌕⋡ߒ㧘ߘߩ
Nᧃ┵ߦ
10,12- ࡍࡦ࠲ࠦࠨࠫࠗࡦ㉄ࠍዉߒߚᣂⷙࠫࠕ
࠴ࡦဳࡍࡊ࠴࠼⢽⾰ (1) ࠍಽሶ⸳⸘ߒߚ (Figure 1) 㧚వߦ߽ㅀߴߚ߇㧘ಽሶ㈩߇ㆡಾߦᓮߐࠇߚ
ࠫࠕ࠴ࡦၮߪ㧘శߥߤߩᾖߦࠃࠅ࠻ࡐࠤࡒࠞ
࡞㊀ว߇ㅴⴕߒ㧘ࡐࠫࠕ࠴ࡦࠍ↢ᚑߔࠆ㧚 Baughman ࠄ
24-25)ߦࠃࠆߣࠫࠕ࠴ࡦၮߩ㊀ᔃ〒
㔌߇ 0.47 ~ 0.52 nm, 1,4 ߩ⚛㑆〒㔌߇ 0.34 ~
0.40 nm, ࡕࡁࡑಽሶゲߣࠬ࠲࠶ࠠࡦࠣゲߣߩⷺ
ᐲ߇ 45 qߢࠆߣ߈㧘࠻ࡐࠤࡒࠞ࡞㊀ว߇ലᨐ⊛ߦ ㅴⴕߒ㧘ࡐࠫࠕ࠴ࡦ߇↢ᚑߔࠆߣႎ๔ߐࠇߡ
ࠆ㧚৻ᣇߢ㧘 L
4K
8L
4߇
E-ࠪ࠻᭴ㅧࠍᒻᚑߒߚ ߣ߈ߩ
E-ࠬ࠻ࡦ࠼㎮㑆ߩ〒㔌ߪ 0.47 nm ߢࠅ㧘 ߎࠇߪࠫࠕ࠴ࡦߩ࠻ࡐࠤࡒࠞ࡞㊀ว߇ലᨐ⊛
ߦㅴⴕߔࠆ᧦ઙߣ৻⥌ߔࠆ㧚ᓥߞߡ㧘
1ߩ᳓ਛߢߩ
⥄Ꮖ㓸วᒻᘒߦࠃߞߡߪ㧘ࠫࠕ࠴ࡦၮߩ࠻ࡐࠤ ࡒࠞ࡞㊀ว߽น⢻ߢࠆߣ⠨߃ࠄࠇ㧘⚿วߦࠃ ࠆ࠽ࡁ⚵❱ߩቯൻ߽ᦼᓙߐࠇࠆ㧚
1ߪ Fmoc ࿕
⋧วᚑᴺࠍㆡ↪ߔࠆߎߣߢวᚑߔࠆߎߣ߇ߢ߈㧘
MALDI-TOFMS ߅ࠃ߮
1H-NMR ࠃࠅಽሶ㊂߅ࠃ߮
ᵋ㏸ࢅ☔ヾࡊࡒ㸣
Ề୯࡞࠽ࡄࡾࢩࢬࢲࣝࣤᆵ࣋ࣈࢲࢺ⬙㈹
ࡡḗᵋ㏸࡞࠽ࡻࡌ S+ ࡡᙫ㡢㻃
ࡱࡍ㸡ࢩࢬࢲࣝࣤᆵ࣋ࣈࢲࢺ⬙㈹
(1)
ࡡỀ୯࡚ࡡḗᵋ㏸≁ᛮ࡞ࡗ࠷࡙᳠ゞࡊࡒ㸣Figure 2 ࡢᵕࠍ
pH
ࡡỀ୯࡞࠽ࡄࡾCD
ࢪ࣋ࢠࢹࣜࢅẒ㍉ࡊࡒࡵࡡ࡚࠵ࡾ㸣ᑠ㸡ࡆࡿࡼࡡࢪ࣋ࢠࢹࣜࡢ㸡ࢦࣤࣈࣜㄢ
⿿├ᚃ࡞ῼᏽࡊࡒ㸣ࡆࡿࡻࡽ
pH 3.9
ࡡỀ୯࡚ࡢ㸡198 nm
࡞࣋ࣈࢲࢺ⤎ྙࡡ π-π* 㐼⛛࡞ᇱࡘࡂㇿࡡࢤࢴࢹࣤຝᯕずࡼࡿࣚࣤࢱ࣑ࢤࣜᵋ㏸ࢅᙟᠺ ࡊ࡙࠷ࡾ㸡pH୕᪴ࡌࡾ࡛
218 nm
࡞n-π* 㐼⛛࡞ᇱࡘࡂㇿࡡࢤࢴࢹࣤຝᯕ,
195 nm
࡞ π-π* 㐼⛛࡞ᇱࡘࡂḿࡡࢤࢴࢹࣤຝᯕ☔ヾ࡚ࡀ β-ࢨ࣭ࢹᵋ
㏸26)࡞ᵋ㏸㌷⛛ࡌࡾࡆ࡛ࢂ࠾ࡾ㸣
Figure 2(B)
࡞㸡 ࡆࡡ࡛ࡀࡡࣚࣤࢱ࣑ࢤࣜᵋ㏸࡞ᇱࡘࡂ198 nm
ࡡ࣓ࣜළ⋙
([θ]
198)
࡛pH
ࡡ㛭౿ࢅࣈࣞࢴࢹࡊࡒ㸣⮾࠷ࡆ࡛࡞㸡 pH 4.0 ㎾ࡡ㓗ᛮ᮪௲࡞࠽࠷࡙
198 nm
ࡡ[θ]
ೋㇿ࠾ࡼḿ࡞ንࢂࡽ㸡ࡆࡡ㡷ᇡ࡚ࣚࣤࢱ࣑ࢤࣜᵋ㏸࠾ࡼ β-ࢨ࣭ࢹᵋ㏸ࡡḗᵋ
㏸㌷⛛⏍ࡋ࡙࠷ࡾࡆ࡛ࢂ࠾ࡾ㸣ୌ᪁㸡ࡆࡿࡱ࡚
ࡡ◂✪࠾ࡼ㸡ࢩࢬࢲࣝࣤᇱࢅᑙථࡊ࡙࠷ ࠷
L
4K
8L
4ࡢpH 9.0
㎾࡚ࡆࡡࡻ࠹ᵋ㏸㌷⛛⏍ࡋࡾࡆ࡛ࡌ࡚࡞᪺ࡼ࠾࡞ࡈࡿ࡙࠷ࡾ㸣ࡆࡿࡢ
L
4K
8L
4
pH 9.0
௧ୖ࡚ࡢࣛࢨࣤഁ㙈ࡡ࣐ࢿᇱࣈࣞࢹࣤࡊ㸡ࡐࡡ㟴㞹ཬⓆ࡞ࡻࡽࣚࣤࢱ࣑ࢤࣜᵋ㏸ࢅ
ᙟᠺࡌࡾ㸡
pH 9.0
௧୕࡚ࡢࣛࢨࣤഁ㙈ࡡ⬲ࣈࣞࢹࣤ࡞ఔ࠹㟴㞹ཬⓆࡡゆᾐ࡞ࡻࡽࣞࢨࣤ㒂న㛣 ࡡỀᛮ┞பష⏕ඁເ࡛ࡽ࣋ࣈࢲࢺฦᏄྜྷኃ
㞗ྙࡊ࡙㸡ฦᏄ㛣࡚Ề⣪⤎ྙࢅᙟᠺࡌࡾࡒࡴ࡛⩻
࠻ࡼࡿ࡙࠷ࡾ㸣ࡊ࠾ࡊࡼ㸡1ࡢỀᛮࡡ㧏࠷㛏 㙈ࣜ࢞ࣜᇱᑙථࡈࡿ࡙࠷ࡾࡒࡴ㸡Ề୯࡚ࡡ࣋ࣈ
ࢲࢺ㙈ࡡ㞗ྙⴥࡊࡂಀ㐅ࡈࡿ㸡ࣛࢨࣤഁ㙈࣐ࢿ
ᇱࣈࣞࢹࣤࡌࡾ࡛⩻࠻ࡼࡿࡾ㓗ᛮ᮪௲ୖ࡞࠽
࠷࡙ࡵ β-ࢨ࣭ࢹᵋ㏸ࡡᙟᠺヾࡴࡼࡿࡒࡵࡡ࡛᥆ ᐳࡈࡿࡾ㸣ࡌࢂࡔ㸡࣋ࣈࢲࢺᮆ❻ࡡ㛏㙈ࣜ࢞
ࣜᇱࡡᑙථࡢ㸡Ề୯࡚ࡡḗᵋ㏸≁ᛮ࡞ኬࡀࡂᙫ㡢 ࡌࡾࡆ࡛ࡢ᪺ࡼ࠾࡚࠵ࡾ㸣
Ề୯࡞࠽ࡄࡾࢩࢬࢲࣝࣤᆵ࣋ࣈࢲࢺ⬙㈹
ࡡ⮤ᕤ㞗ྙ≁ᛮ
ࡐࡆ࡚ḗ࡞Ề୯࡞࠽ࡄࡾࢩࢬࢲࣝࣤᆵ࣋ࣈࢲ ࢺ⬙㈹
(1)
ࡡ⮤ᕤ㞗ྙ≁ᛮ࡞㛭ࡌࡾ▩ずࢅᚋࡾࡒࡴ㸡
pH 9.0
࡛pH 3.9
࡞࠽࠷࡙ḗᵋ㏸ࡡ⤊ንࡼࡦ࡞ࢻࢿ㞗ྙᵋ㏸ࡡ᳠ゞࢅ⾔ࡖࡒ㸣Figure 3(A)
ࡢ
pH 9.0
࡞࠽ࡄࡾCD
ࢪ࣋ࢠࢹࣜࡡ⤊ንࢅẒ㍉ࡊࡒࡵࡡ࡚࠵ࡾ㸣ࡆࡡ᮪௲ୖ࡞࠽࠷࡙ 1ࡢ⁈ᾦࢅㄢ
⿿ࡊࡒ├ᚃ࠾ࡼ β-ࢨ࣭ࢹᵋ㏸ࢅᙟᠺࡊ㸡
24
㛣ᚃ࡞࠽࠷࡙ࡵࢪ࣋ࢠࢹࣜ࡞ንࡢ࡛ࢆヾࡴࡼࡿ
࠾ࡖࡒ㸣ࡱࡒ
Figure 3(B)
ࡢ㸡24
㛣ᚃ࡞ᚋࡼࡿࡒ
AFM
ാ࡚࠵ࡾ㸡⢇≟ࡡ㞗ྙమ࠽ࡻࡦࡐࡿࡼฆ㞗ࡊࡒᵋ㏸ࡡࡲびᐳࡈࡿࡒ㸣ᑠ㸡ࡐࡡࢦࢫ࡞
ᆍୌᛮࡢずࡼࡿ࠾ࡖࡒ㸣ࢩࢬࢲࣝࣤᇱࢅࡵࡒ
࠷
L
4K
8L
4ࡢ㸡ࡆࡡ᮪௲ୖ࡞࠽࠷࡙ࣞࢨࣤ㛣ࡡỀᛮ┞பష⏕ࡷࣛࢨࣤ㛣ࡡ㟴㞹┞பష⏕ࣁࣚࣤ
ࢪࡻࡂ഼ࡂࡆ࡛࡞ࡻࡽ㸡ぜ์Ⓩ࡞⮤ᕤ⤄⧂ࡊ࡙㸡 β-ࢨ࣭ࢹᵋ㏸ࢅᇱᮇ࡛ࡌࡾ㧏ࡈ⣑ 5-6 nmࡡࢻࢿࣆ
Figure 2. (A) CD spectra of 1 in 5 mM-buffer solutions (containing 5 % TFE) at various pHs, room temperature.
(B) pH-dependence of molar ellipticity at 198 nm ([θ]198) of1 estimated from CD spectra. [1] = 40 μM.
ࠔࠗࡃࠍᒻᚑߔࠆ㧚1ߢߪ⇹᳓ᕈߩ㜞㐳㎮ࠕ࡞
ࠠ࡞ၮࠍࡍࡊ࠴࠼ᧃ┵ߦዉߒߡࠆߚ㧘᳓ਛߢ ಽሶ߇ᕆㅦߦ㓸วߒ㧘ߘߩ⚿ᨐࠕࡕ࡞ࡈࠔࠬߥಝ㓸
ࠍᒻᚑߒߚ߽ߩߣ⠨߃ࠄࠇࠆ㧚
৻ᣇ㧘
pH 3.9
ߢߪ1ߩ⥄Ꮖ㓸ว․ᕈߪᄢ߈ߊ⇣ߥߞߚ㧚ߔߥࠊߜ㧘1ߪṁᶧ⺞⋥ᓟߦ߅ߡߪࡦ
࠳ࡓࠦࠗ࡞᭴ㅧߣߒߡሽߒߡࠆ߇㧘ᤨ㑆ߩ⚻ㆊ
ߦ
215 nm
ߦ߅ߌࠆࡕ࡞ᬦ₸߇⽶ߦჇടߒߡ߈㧘E-ࠪ࠻᭴ㅧߦ᭴ㅧォ⒖ߔࠆߎߣ߇ࠊ߆ߞߚ
(Figure 4)
㧚߹ߚᝌ࿑ߪ㧘215 nm
ߩࡕ࡞ᬦ₸ߣᤨ㑆ߩ㑐ଥࠍࡊࡠ࠶࠻ߒߚ߽ߩߢࠆ߇㧘ੑᰴ᭴ㅧ ォ⒖ߪ
100
ᤨ㑆⒟߆ߌߡ✭߿߆ߦㅴⴕߔࠆߎߣ߽ࠄ߆ߣߥߞߚ㧚 ߘߎߢ㧘ߎߩᤨߩੑᰴ᭴ㅧォ⒖ߦ
߁ࡕ࡞ࡈࠜࡠࠫߩ⚻ᤨᄌൻࠍ
AFM
ࠃࠅᬌ⸛ߒ ߚ㧚Figure 5
ߪpH 3.9
ߦ߅ߌࠆ1ߩṁᶧ⺞⋥ᓟ㧘24
ᤨ㑆ᓟ߅ࠃ߮100
ᤨ㑆ᓟߩAFM
ࠍᲧセߒߚ߽ߩߢࠆ㧚ߎࠇࠃࠅ㧘1߇ࡦ࠳ࡓࠦࠗ࡞᭴ㅧࠍ
ᒻᚑߒߡࠆṁᶧ⺞⋥ᓟߢߪ㧘৻ㇱ⁁ߩ᭴ㅧ߇ ሽߔࠆ߽ߩߩ⏕ߥ㓸ว᭴ㅧߪࠄࠇߥ
(Figure 5A)
㧚߅ߘࠄߊᄢㇱಽߪಽሶಽᢔߒߚ⁁ᘒߢሽߒߡࠆ߽ߩߣᕁࠊࠇࠆ㧚ߣߎࠈ߇㧘
24
ᤨ㑆 ᓟߢߪࡈࠔࠗࡃ⁁ߩ᭴ㅧ߇ⷰኤߐࠇߪߓ(Figure 5B)
㧘ߐࠄߦ100
ᤨ㑆ᓟߢߪ㧘ࠃࠅᚑ㐳ߒߚ ᄙߊߩࡈࠔࠗࡃ⁁ߩ᭴ㅧ߇ⷰኤߐࠇߚ(Figure 5C)
㧚ߔߥࠊߜ㧘ᤨ㑆ߩ⚻ㆊߦࠃࠆ E-
ࠪ࠻ൻߦFigure 4. CD spectral change of 1 in 5 mM-phosphate buffer (containing 5% TFE) at pH 3.9, room temperature.
[1] = 40 PM.
Figure 3. (A) Time-dependence of CD spectra of 1 in 5 mM-Tris/HCl buffer (containing 5% TFE) at pH 9.0, room temperature. [1] = 40 PM. (B) Tapping-mode AFM image of 1 obtained after incubation for 24 h at above condition.
Figure 5. Tapping-mode AFM images of 1 obtained just after sample preparation (A), and after incubation for 24 h (B) and 100 h (C) in 5 mM-phosphate buffer (containing 5%
TFE) at pH 3.9. [1] = 40 PM. (D) Cross-sectional analysis of 1-nanofibers.
㧘1ߪ࠽ࡁࡈࠔࠗࡃ᭴ㅧ߳⥄Ꮖ⚵❱ൻߔࠆߎߣ ߇ࠊ߆ߞߚ㧚 ߎߩ࠽ࡁࡈࠔࠗࡃߪ㜞ߐ
19 23 nm
ߢ ࠅ(Figure 5D)
㧘 ߎ ࠇ ߪ એ ೨ ߦ ႎ ๔ ߐ ࠇ ߚL
4K
8L
4߇pH 9.0
ߢᒻᚑߔࠆ࠽ࡁࡈࠔࠗࡃ (㜞ߐ 5–6nm)
10) ߩ4
ߩᄥߐߦ⋧ᒰߔࠆ㧚1߇ E-ࠪ࠻᭴ㅧࠍᒻᚑߒߚߣ߈ߩℂ⺰ಽሶ㐳ߪ⚂
8.7 nm
ߢࠅ㧘ߎߩ୯ߪⷰኤߐࠇߚ1-࠽ࡁࡈࠔࠗࡃߩ⋥ᓘ ߩ⚂ඨಽߦߚࠆ㧚ᓥߞߡ㧘1߇ᒻᚑߔࠆ࠽ࡁࡈࠔ
ࠗࡃߪࠫࠕ࠴ࡦၮࠍ⇹᳓ᕈࠕ࡞ࠠ࡞㎮
ࠍࠦࠕߦ㧘Ყセ⊛ⷫ᳓⊛ߥࡍࡊ࠴࠼ࠣࡔࡦ࠻ࠍࠪ
ࠚ࡞ߣߔࠆࡠ࠶࠼⁁ߩࡒ࡞ࡈࠔࠗࡃߢࠆߣ ផኤߐࠇࠆ(Figure 6)㧚ߎߩࠃ߁ߦ㧘
L
4K
8L
4ࡍࡊ࠴࠼ߦ⇹᳓ᕈߩ㜞⋥ߥࠫࠕ࠴ࡦဳࠕ࡞ࠠ࡞㎮
ࠍዉߔࠆߎߣߢ㧘᳓ਛߢߩ⥄Ꮖ㓸ว᭽ᑼ߇ᄌൻߒ㧘
⇣ߥࠆ࠽ࡁ᭴ㅧߦ⥄Ꮖ⚵❱ൻߔࠆߎߣ߇ࠊ߆ߞ ߚ㧚
߹ߚ㧘࠽ࡁࡈࠔࠗࡃ᭴ㅧߦ⥄Ꮖ⚵❱ൻߒߚᓟ
(100
ᤨ㑆ᓟ)
ߩ1-᳓ṁᶧ(pH 3.9)
ߦUV
శࠍᾖߒ ߡశ㊀ว․ᕈࠍᬌ⸛ߒߚ߇㧘ࡐࠫࠕ࠴ࡦߦၮ ߠߊๆߪⷰኤߐࠇߕ, ㊀วߪㅴⴕߒߥ߆ߞߚ㧚 ᚒޘߪ E-ࠪ࠻࠽ࡁࡈࠔࠗࡃࠍ࠹ࡦࡊ࠻ߣߔࠆࠫࠕ࠴ࡦၮߩ৻ᰴరⷙೣ㈩ࠍᦼᓙߒ ߡߚ㧚ߒ߆ߒߥ߇ࠄ㧘ᧄ⎇ⓥߢណ↪ߒߚ
10,12-
ࡍࡦ࠲ࠦࠨࠫࠗࡦ㉄ߪ⚛ᢙ߇ᄙߊ⇹᳓ᕈ߇㜞ߚ㧘᳓ਛߦ߅ߡࡍࡊ࠴࠼㑆ߩ⋧↪ࠃࠅ
߽ߒࠈࠕ࡞ࠠ࡞㎮㑆ߩ⋧↪߇ఝవ⊛ߦ
߈㧘ࡒ࡞᭽ߩࡈࠔࠗࡃ᭴ㅧߦ⥄Ꮖ⚵❱ൻߒߡ ߒ߹߁ߚ㧘⚿ᨐߣߒߡࠫࠕ࠴ࡦၮߩ࠻ࡐࠤ ࡒࠞ࡞㊀วߦㆡߒߚಽሶ㈩߇㆐ᚑߐࠇߥ߆ߞ ߚ߽ߩߣᕁࠊࠇࠆ㧚
⚿⸒
ᧄ ⎇ ⓥ ߢ ߪ ਔ ⷫ ᇦ ᕈ ࠻ ࡉ ࡠ ࠶ ࠢ ࡍ ࡊ ࠴ ࠼
L
4K
8L
4 ߩNᧃ┵ߦ10,12-
ࡍࡦ࠲ࠦࠨࠫࠗࡦ㉄ࠍዉߒߚࠫࠕ࠴ࡦဳࡍࡊ࠴࠼⢽⾰
(1)
ࠍᣂⷙߦ ಽሶ⸳⸘วᚑߒ㧘᳓ਛߦ߅ߌࠆੑᰴ᭴ㅧ߅ࠃ߮⥄Ꮖ㓸ว․ᕈߦߟߡᬌ⸛ߒߚ㧚ߘߩ⚿ᨐ㧘᳓ਛߢߩ 1ߩ⥄Ꮖ㓸ว․ᕈߪ㧘
L
4K
8L
4ࡍࡊ࠴࠼ߣߪ⪺ߒߊ⇣ߥࠆߎߣ߇ࠊ߆ߞߚ㧚ߔߥࠊߜ㧘
L
4K
8L
4ߪࠪࡦ㎮ࠕࡒࡁၮߩ
pK
aઃㄭ(pH 9.0)
ߦ߅ߡ⥄Ꮖ㓸ว ߒߡ E-ࠪ࠻࠽ࡁࡈࠔࠗࡃ(
㜞ߐ 5-6 nm)ࠍᒻ ᚑߔࠆߩߦኻߒߡ㧘 1ߪ㉄ᕈ᧦ઙਅ(pH 3.9)
ߦ߅ߡࡦ࠳ࡓࠦࠗ࡞᭴ㅧ߆ࠄ E-ࠪ࠻᭴ㅧ߳ߩ᭴
ㅧォ⒖߇ㅴⴕߒ㧘㜞ߐ⚂
20 nm
ߩ࠽ࡁࡈࠔࠗࡃߦ⥄Ꮖ⚵❱ൻߔࠆߎߣ߇ࠊ߆ߞߚ㧚ߎߩ࠽ࡁࡈࠔࠗࡃ
ߪ㧘ࠫࠕ࠴ࡦㇱࠍࠦࠕߣߔࠆࡠ࠶࠼⁁ࡒ
࡞ࡈࠔࠗࡃߢࠆߣផ᷹ߐࠇࠆ㧚ߒ߆ߒߥ߇ࠄ㧘
࿁㧘1-࠽ࡁࡈࠔࠗࡃਛߦ߅ߌࠆࠫࠕ࠴ࡦၮ ߩ࠻ࡐࠤࡒࠞ࡞㊀วߪࠄࠇߥ߆ߞߚ㧚㧘ᓧ ࠄࠇߚ⍮ࠍ߽ߣߦ㧘ᣂߚߥࠫࠕ࠴ࡦဳࡍࡊ࠴
࠼⢽⾰ࠍಽሶ⸳⸘ߒ㧘㊀วᕈࡍࡊ࠴࠼࠽ࡁࡈࠔࠗ
ࡃߩ㐿⊒ࠍㅴߡࠆ㧚
ᧄ⎇ⓥߩ৻ㇱߪ㧘ᢥㇱ⑼ቇ⋭⑼ቇ⎇ⓥ⾌ഥ㊄
(17710104)
߅ࠃ߮ᢥㇱ⑼ቇ⋭ቇⴚࡈࡠࡦ࠹ࠖࠕផㅴᬺޟකᎿቇ⎇ⓥߩᣂዷ㐿หᔒ␠ᄢቇޠߩᡰេ
ࠍ߁ߌߡⴕߞߚ㧚ߎߎߦ⸥ߒߡ⻢ᗧࠍߔࠆ㧚
ෳ⠨ᢥ₂
1) L. M. Pakstis, B. Ozbas, K. D. Hales, A. P. Nowak, T. J.
Deming, D. Pochan, Biomacromolecules, 5, 312 (2004).
2) W. A. Petka, J. L. Harden, K. P. McGrath, D. Wirth, D. A.
Tirrell, Science, 281, 389 (1998).
3) J. D. Hartgerink, E. Beniash, S. I. Stupp, Science, 294, 1684 (2001).
Figure 6. Plausible model of 1-nanofiber observed after incubation for 100 h in phosphate buffer at pH 3.9.
4) S. Matsumura, S. Uemura, H. Mihara, Chem. Eur. J., 10, 2789 (2004).
5) H. A. Lashuel, S. R. LaBrenz, L. Woo, L. C. Serpell, J. W.
Kelly, J. Am. Chem. Soc., 122, 5262 (2000).
6) T. Koga, K. Taguchi, Y. Kobuke, T. Kinoshita, M. Higuchi, Chem. Eur. J., 9, 1146 (2003).
7) T. Koga, K. Kitamura, N. Higashi, Chem. Commun., 4897 (2006).
8) G. W. Vandermeulen, C. Tziatzions, H. A. Klok, Macromolecules, 36, 4107 (2003).
9) T. Koga, M. Matsuoka, N. Higashi, J. Am. Chem. Soc., 127, 17596 (2005).
10) T. Koga, M. Higuchi, T. Kinoshita, N. Higashi, Chem.
Eur. J., 12, 1360 (2006).
11) G. Z. Wegner, Naturforsch, 246, 824 (1969).
12) R. R. Chance, R. H. Baughman, H. Muller, J. Eckhardt, J. Chem. Phys., 67, 3616 (1977).
13) A. S. Alekseev, T. Viitala, I. N Domnin, I. M. Koshkina, Langmuir, 16, 3337 (2000).
14) U. G Hofmann, J. Peltonen, Langmuir, 17, 1518 (2001).
15) M. Niwa, T. Ishida, T. Kato, N. Higashi, J. Mater. Chem., 8, 1697 (1998).
16) D. J. Ahn, E. H. Chae, G. S. Lee, H. Y. Shim, T. E. Chang, K. D. Ahn, J. M. Kim, J. Am. Chem. Soc., 125, 8976 (2003).
17) T. Kim, K. C. Chan, R. M. Crooks, J. Am. Chem. Soc., 119, 189 (1997).
18) D. W. Mosley, M. A. Sellmyer, E. J. Daida, J. M.
Jacobson, J. Am. Chem. Soc., 125, 10532 (2003).
19) J. M. Kim, J. S. Lee, H. Choi, D. Sohn, D. J. Ahn, Macromolecules, 38, 9366 (2005).
20) M. Masuda, T. Hanada, Y. Okada, K. Yasu, T. Shimizu, Macromolecules, 33, 9233 (2000).
21) D. A. Frankel, D. F. Obrein, J. Am. Chem. Soc., 113, 7436 (1991).
22) J. H. Fuhrhop, P. Blumtritt, C. Lehmann, P. Luger, J. Am. Chem. Soc., 113, 7437 (1991).
23) S. J. Lee, C. R. Park, J. Y. Chang, Langmuir, 20, 9513 (2004).
24) R. H. Baughman. J. Polym. Sci., Polym. Phys. Ed., 12, 1511 (1974).
25) R. H. Baughman.; K. C. Yee, J. Polym. Sci., Macromol.
Rev., 13, 219 (1978).
26) N. Greenfield, G.D. Fasmsn, Biochemistry, 8, 4108 (1969).
