Self-Assembled Peptide Architecture with a Tooth Shape: Folding into Shape

Transcription

1 Supporting Information for Self-Assembled Peptide Architecture with a Tooth Shape: Folding into Shape Table of Contents 1. Materials S2 2. Self-Assembly Procedures S2 3. Experimental Section S2 4. Supporting Figures and Tables S4 Supporting Figure S1 S4 Supporting Figure S2 S4 Supporting Figure S3 S5 Supporting Figure S4 S5 Supporting Figure S5 S6 Supporting Figure S6 S6 Supporting Figure S7 S7 Supporting Figure S8 S8 Supporting Figure S9 S9 Supporting Figure S10 S9 Supporting Figure S11 S10 Supporting Figure S12 S10 Supporting Table S1 S11 Supporting Table S2 S12 5. References S13 S1

2 Materials All chemicals for the preparation of the ACPC 6 were purchased from Sigma Aldrich, Acros, Junsei, and TCI, and were used without further purification. High purity water was generated by Milli-Q apparatus (Millipore). The synthesis of the hexamer was performed by following the literature protocol. 1,2 Self-assembly M P : A solution of ACPC 6 in THF (50 L, 2 mg ml -1 ) was added to an aqueous solution of P123 (2 ml, 8 g L -1 ) with vigorous stirring for 1 min at 0 o C. The agitated solvent mixture was then maintained for 3 h at 20 o C. The resulting solution was centrifuged, and the supernatant was decanted. The residual white powder of assembly was washed with distilled water to remove P123 and THF. X P : A solution of ACPC 6 in THF (50 L, 2 mg ml -1 ) was added to an aqueous solution of P123 (2 ml, 8 g L -1 ) with vigorous stirring for 10 min at 0 o C. The agitated solvent mixture was then maintained for 3 h at the same temperature. The resulting solution was centrifuged, and the supernatant was decanted. The residual white powder of assembly was washed with distilled water to remove P123 and THF. X W : A solution of ACPC 6 in THF (50 L, 2 mg ml -1 ) was added to distilled water (2 ml) with vigorous stirring for 1 min at 0 o C. The agitated solvent mixture was then maintained for 3 h at 20 o C. The resulting solution was centrifuged, and the supernatant was decanted. The residual white powder of assembly was washed with distilled water to remove P123 and THF. Experimental Section The prepared dispersion of the assemblages was transferred to a Si(100) wafer and dried under air. SEM images were obtained by using a field-emission scanning electron microscope (FE-SEM, Hitachi S-4800, Japan) at an acceleration voltage of 10 kv after Pt coating (SCD 050 platinum evaporator, Bal-tec, Germany). TGA was carried out by using a TG 209 F3, with an increase in S2

3 temperature of 10 o C min -1 (NETZSCH, Germany). Infrared spectra were obtained by using an ALPHA FTIR spectrometer ATR module (Bruker optics, USA). The circular dichroism signal was measured by a Jasco-815 spectrometer (Jasco. Inc., Japan) by using methanolic solutions of hexamer, sample cells with a path length of 1 mm were used. Powder X-ray diffraction patterns for assemblages M P, X P were obtained from a multi-purpose attachment X-ray diffractometer (Rigaku, D / Max-2500) equipped with a pyrolytic graphite (002) monochromator. Characteristic Cu K radiation was used as an incident beam ( = Å) and the diffraction patterns were scanned over 2 values ranging from 2 o up to 50 o in increments of 0.02 o at room temperature. For detailed structural analysis of molar tooth-shaped assemblage, M P, the synchrotron diffraction data were collected on the 8C2 beamline at Pohang Acceleration Laboratory (Pohang, Korea) using monochromatic synchrotron radiation ( = Å). The detector arm of the vertical scan diffractometer consists of seven sets of Soller slits, flat Ge(111) crystal analyzers, anti-scatter baffles, and scintillation detectors, with each set separated by 20 o. Data were obtained on the sample at room temperature in flat plate mode, with a step size of 0.01 o for a scan time of 5s per step and overlaps of 2 o to the next detector bank over the 2 range o. Profile refinement of the structure model was performed via the Le Bail method with the GSAS package. The profile was matched in the 2 range 7 51 o because of the overlap of the peak at d < 1.8 Å, and the poor signal to noise ratio of the data at very high angles. During the Rietveld refinement, a pseudo-voigt/fcj function, together with a manually interpolated background, was used to describe the peak shape. S3

4 Supporting Figure S1. Circular dichroism data for trans-(r,r)-acpc 6 in methanol solution (2.3 mm). Data were collected on a Jasco J-815 spectrometer at 20 o C. The signal (a maximum at ~204 nm and a minimum at ~221 nm) indicates that the ACPC hexamer adopts stable left-handed 12-helix. Supporting Figure S2. Tilted-view SEM images of self-assembled structures of M P. S4

5 Supporting Figure S3. SEM image of self-assembled structure of trans-(r,r)-acpc 6 obtained from distilled water (X W ). Supporting Figure S4. SEM image of self-assembled structures of trans-(s,s)-acpc 6 obtained from P123 8g L -1. We observed the same SEM images from the self-assembly of the right-handed (S,S)-ACPC 6 that consists of opposite enantiomers at the same condition, suggesting that the helical handedness of the building block is not responsible for the dramatic changes in morphologies from those of (S,S)-ACPC 7. S5

6 Supporting Figure S5. TGA curves of M P and as-prepared powder of ACPC 6. No significant difference between M P and the as-prepared powder was observed in the TGA profiles, in which the weight loss occurred at around 250 o C. It demonstrates that they have higher thermal stability than conventional peptides, and showed the absence of P123 in M P. Supporting Figure S6. FTIR spectra of M P, X P, and as-prepared powder of ACPC 6. The FTIR spectra are identical, which also supports that the assemblies are exclusively consisted of ACPC 6. S6

7 Supporting Figure S7. PXRD patterns of self-assemblages with different morphologies obtained from multi-purpose attachment X-ray diffractometer (Rigaku, D / Max-2500) (red: M P, black: X P ). The PXRD pattern of X P could be indexed to give almost same crystallographic lattice parameters as those of the molar tooth shape M P. S7

8 Supporting Figure S8. (a) Experimental X-ray powder diffraction pattern of ACPC 6. (b) Le Bail fitting of (a) using P4 1 space group. (c) Simulated X-ray diffraction pattern of single ACPC 6 unit using P1 space group with the single crystal structure data. 2 The tick mark represents the Bragg diffraction peak corresponding to P4 1 space group. S8

9 Supporting Figure S9. Rietveld refinement plot for M P using the PXRD data at 300K with the following synchrotron diffraction powder patterns: observed (upper), calculated (middle), and difference (lower). The tick marks indicate the allowed reflection positions Supporting Figure S10. The refined structure of Boc-[trans-(R,R)-ACPC] 6 -OBn in M P showing the intermolecular (red) and intramolecular (light blue) hydrogen bonds after the addition of hydrogen. S9

10 Supporting Figure S11. (a) The refined final structure of ACPC 6, viewed perpendicular to the helix axis. The intra- (C=O(i)--H-N(i+3), light blue) and intermolecular (red) hydrogen bonds are shown as dotted lines. With the exception of the amide hydrogens, the hydrogen atoms are omitted for clarity (N-terminus, top); (b) Superposition of the initial (gray-white) and refined (pink) final structures of the ACPC 6 units. Supporting Figure S12. The helical structure of ACPC 6 units in the unit cell: (left) along the b axis and (right) along the c axis. S10

11 Supporting Table S1. Data Collection and Crystallographic Parameters for ACPC 6. Material ACPC 6 unit cell composition refined structure C48 N6 O9 (Z=4) symmetry Tetragonal space group P4 1 a, Å (35) b, Å (35) c, Å (29) cell volume, Å (5) diffractometer 8C2, PAL temperature, o C room temperature wave length, Å scan range, o, no. observations no. contributing reflections no. geometric restraints 157 no. structural parameters 241 R p, % 5.46 R wp, % 7.65 R F, % 8.24 S11

12 Supporting Table S2. Atomic Coordinates and Displacement and Population Parameters for ACPC 6. atom X y z occupancy U iso, 10 2 Å 2 multiplicity C (19) (23) (219) (68) 4 C (18) (21) (33) (68) 4 C (20) (19) (33) (68) 4 C (13) (12) (21) (68) 4 O (13) (11) (29) (47) 4 O (16) (19) (32) (47) 4 C (12) (15) (33) (47) 4 N (18) (22) (35) (47) 4 C (15) (19) (32) (21) 4 C (20) (14) (32) (21) 4 C (17) (18) (30) (21) 4 C (18) (16) (33) (21) 4 C (17) (15) (35) (21) 4 O (15) (14) (29) (15) 4 C (20) (18) (31) (15) 4 N (16) (15) (31) (15) 4 C (14) (16) (35) (21) 4 C (17) (15) (32) (21) 4 C (17) (16) (29) (21) 4 C (14) (20) (32) (21) 4 C (19) (14) (33) (21) 4 O (14) (12) (26) (15) 4 C (19) (15) (32) (15) 4 N (13) (13) (27) (15) 4 C (12) (12) (25) (21) 4 C (14) (16) (30) (21) 4 C (14) (19) (34) (21) 4 C (18) (13) (37) (21) 4 C (12) (17) (34) (21) 4 O (14) (14) (28) (15) 4 C (16) (18) (30) (15) 4 N (13) (14) (27) (15) 4 C (12) (13) (27) (21) 4 C (19) (14) (33) (21) 4 C (15) (19) (33) (21) 4 C (22) (14) (32) (21) 4 S12

13 C (14) (17) (30) (21) 4 O (14) (14) (26) (15) 4 C (17) (20) (29) (15) 4 N (16) (16) (29) (15) 4 C (15) (19) (32) (21) 4 C (18) (14) (34) (21) 4 C (21) (16) (32) (21) 4 C (16) (17) (31) (21) 4 C (17) (15) (30) (21) 4 O (14) (14) (29) (15) 4 C (17) (16) (31) (15) 4 N (11) (14) (23) (15) 4 C (12) (11) (25) (21) 4 C (18) (19) (25) (21) 4 C (19) (13) (34) (21) 4 C (20) (17) (28) (21) 4 C (13) (10) (24) (21) 4 O (18) (18) (27) (47) 4 C (16) (10) (21) (47) 4 O (16) (11) (27) (47) 4 C (15) (16) (31) (47) 4 C (12) (11) (23) (85) 4 C (18) (14) (23) (85) 4 C (24) (11) (30) (85) 4 C (19) (14) (27) (85) 4 C (20) (14) (27) (85) 4 C (17) (11) (32) (85) 4 References (1) P. R. LePlae, N. Umezawa, H.-S. Lee, S. H. Gellman, J. Org. Chem. 2001, 66, (2) Appella, D. H.; Christianson, L. A.; Klein, D. A.; Richards, M. R.; Powell, D. R.; Gellman, S. H. J. Am. Chem. Soc. 1999, 121, S13