Supporting Information Developing Activity Localization Fluorescence Peptide Probe Using Thiol-Ene Click Reaction for Spatially Resolved Imaging of Caspase-8 in Live Cells Wei Liu,, Si-Jia Liu,, Yong-Qing Kuang *,, Feng-Yan Luo, and Jian-Hui Jiang *, Institute of Chemical Biology & Nanomedicine, State Key Laboratory of Chemo/Biosensing & Chemometrics, College of Chemistry & Chemical Engineering, Hunan University, Changsha 410082, China Guangxi Collaborative Innovation Center for Biomedicine & School of Preclinical Medicine, Guangxi Medical University, Nanning 530021, China These authors contributed equally * Corresponding Author. Fax: +86-731-88821916; E-mail: jianhuijiang@hnu.edu.cn, yqkuang@hnu.edu.cn S-1
Table of Contents Instrumentation...S-3 Scheme S1. Synthetic route to CHCQ...S-3 Synthesis of 2-(5 -chloro-2-hydroxyl-phenyl)-6-chloro-4(3h)-quinazolinone(chcq)...s-3 Scheme S2. Synthetic route to the ALF probe...s-3 Synthesis of 4-chloro-2-formylphenyl acrylate (1)...S-4 Synthesis of the acryloylated CHCQ...S-4 Synthesis of ALF probe...s-4 Extraction of negative and positive HeLa cell lysate...s-4 References...S-5 Additional figures S1-S17... S-6-S-22 S-2
Instrumentation. 1 H-NMR and 13 C-NMR spectra were acquired on a Bruker DRX-400 NMR spectrometer (Bruker) using tetramethylsilane (TMS) as an internal standard. Mass spectra (MS) were recorded on a LTQ Orbitrap Velos Pro mass spectrometer (Thermo Fisher Scientific, Bremen, Germany) and a LCQ Advantage ion trap mass spectrometry (Thermo Finnigan). UV-vis absorption spectra were plotted using a Shimadzu UV-2450 spectrophotometer with a wavelength interval of 2 nm and fluorescence spectra were collected on an FL-7000 spectrofluorometer (Hitachi, Japan). The ph was verified with a Mettler-Toledo FE20 ph meter. The fluorescence imaging of cells was performed using a Nikon A1plus confocal microscope. Scheme S1. Synthetic route to CHCQ Synthesis of 2-(5 -chloro-2-hydroxyl-phenyl)-6-chloro-4(3h)-quinazolinone (CHCQ). CHCQ was synthesized according to the reported procedure. [S1] 1 H-NMR (400 MHz, d 6 -DMSO) δ (ppm): 13.39 (br, 1H), 12.66 (br, 1H), 8.29 (d, J =2.4 Hz, 1H), 8.09 (d, J =2.0 Hz, 1H), 7.91-7.84 (m, 2H), 7.51-7.48 (m, J =2.0 Hz, 1H), 7.05 (d, J =8.8 Hz, 1H). Scheme S2. Synthetic route to the ALF probe S-3
Synthesis of 4-chloro-2-formylphenyl acrylate (1) Dry triethylamine (Et 3 N, 624 μl, 4.5 mmol, 1.5 equiv) and acryloyl chloride (366 μl, 4.5 mmol, 1.5 equiv) were sequentially added to a solution of 5-chloro-salicylaldehyde (0.47 g, 3.0 mmol) in dry dichloromethane (CH 2 Cl 2, 10 ml) at 0 C. The mixture was stirred for 1h at room temperature and the solvent was removed under reduced pressure to give the crude product, which was further purified by silica gel column chromatography with petroleum ether/ethyl acetate (10:1, v:v) as the eluent to afford compound 1 as a white solid (566 mg, 90 % yield). 1 H-NMR (400 MHz, CDCl 3 ) δ (ppm): 9.99 (s, 1H), 7.76 (d, J = 2.4 Hz, 1H), 7.50-7.47 (m, 1H), 7.12 (d, J = 8.4 Hz, 1H), 6.58 (d, J = 17.6 Hz, 1H), 6.31-6.24 (m, 1H), 6.03 (d, J = 10.4 Hz, 1H); 13 C-NMR (100 MHz, CDCl 3 ) δ (ppm): 186.82, 163.77, 150.20, 134.88, 134.11, 132.18, 129.33, 128.91, 126.62, 124.81; MS(EI): calcd for C 10 H 7 ClO 3 [M + ] m/z 210.0, found 210.0. Synthesis of the acryloylated CHCQ A solution of compound 1 (0.21 g, 1.0 mmol), 2-amino-5-chloro-benzamide (0.17 g, 1.0 mmol), and TsOH H 2 O (19 mg, 0.1 mmol) in ethanol (EtOH, 10 ml) was refluxed for 1 h with stirring and then cooled to 0 C. 2, 3-dichloro-5, 6-dicyano-benzoquinone (DDQ, 0.23 g, 1.0 mmol) was added to the solution and the mixture was stirred at 0 C for another 1 h. The greenish precipitate formed was collected by filtration and washed with cooled EtOH to afford the acryloylated CHCQ (295 mg, 82 % yield). 1 H-NMR (400 MHz, d 6 -DMSO) δ (ppm): 12.81 (br, 1H), 8.07 (d, J = 2.0 Hz, 1H), 7.90-7.84 (m, 2H), 7.73-7.70 (m, 1H), 7.60 (d, J = 8.8 Hz, 1H), 7.45 (d, J = 8.8 Hz, 1H), 6.46 (d, J = 17.2 Hz, 1H), 6.33-6.26 (m, 1H), 6.08 (d, J =10.4 Hz, 1H ); 13 C-NMR (100 MHz, d 6 -DMSO) δ (ppm): 164.03, 161.18, 150.51, 147.51, 147.41, 135.28, 134.59, 132.16, 131.92, 130.82, 130.64, 130.17, 128.57, 127.74, 125.91, 125.35, 122.83; HRMS (ESI): calcd for C 17 H 10 Cl 2 N 2 O 3 [M+H] + m/z 361.0141, found 361.0139. Synthesis of ALF probe Acryloylated CHCQ (36 mg, 0.1 mmol ) in 0.5 ml HPLC-grade DMSO was added into a solution of Z-IETDC peptide (15 mg, 0.02 mmol ) in 4.5 ml of 10 mm Tris-HCl buffer (ph 7.4) under stirring. The mixture was vigorously stirred overnight at 37 C, and then extracted with CHCl 3 to remove unreacted acryloylated CHCQ. The water layer was dried under high vacuum to get ALF probe (20.5 mg, 93 % yield). HRMS (ESI): calcd for C 49 H 57 Cl 2 N 7 O 16 S [M-H] - m/z 1100.2887, found 1100.2881. Extraction of negative and positive HeLa cell lysate S-4
The experiment of extraction of positive HeLa cell lysate was performed as follows: HeLa cells were pretreated with 40 µg/ml MMC in RPMI-1640 medium for 4 h at 37 C. To isolate cytoplasmic components from nuclear ones, the cells were treated with a nuclear protein extraction kit (Beyotime Biotechnology, Wuhan, China) and centrifuged at 3400 rpm for 15 min at 4 C. Extraction of negative HeLa cell lysate is similar to that of positive HeLa cell lysate, except that HeLa cells were not pretreated with MMC. References [S1] Aw. J.; Shao. Q.; Yang. Y.; Jiang. T.; Ang. C.; Xing. B. Chem. Asian J. 2010, 5, 1317-1321. S-5
Figure S1. 1 H-NMR spectra of CHCQ in d 6 -DMSO S-6
Figure S2. 1 H-NMR spectra of compound 1 in CDCl 3 S-7
Figure S3. 13 C-NMR spectra of compound 1 in CDCl 3 S-8
RelativeAbundance Figure S4. MS (EI) spectra of compound 1 in Methanol lw-160504-210 #1 RT: 0.21 AV: 1 NL: 4.81E5 T: + c EI Full ms [49.50-500.50] 100 155.0 90 80 70 60 50 40 30 157.0 182.1 210.0 20 127.0 101.0 10 110.0 128.0 158.0 184.0 281.1 126.0 138.0 212.0 102.1 207.1 113.0 154.0 165.1 181.0 185.1 213.0 282.1 228.0 249.0 254.0 267.0 0 100 120 140 160 180 200 220 240 260 280 300 m/z S-9
Figure S5. 1 H-NMR spectra of the acryloylated CHCQ in d 6 -DMSO S-10
Figure S6. 13 C-NMR spectra of the acryloylated CHCQ in d 6 -DMSO S-11
Relative Abundance Figure S7. HRMS (ESI) spectra of the acryloylated CHCQ in Methanol 1_1#1 RT: 0. 01 AV : 1 NL: 3.82E4 T: FTMS + c ESI Full m s [300.00-400.00] 100 361.0139 90 80 70 60 50 363.0108 40 30 20 340.1113 344. 9502 395.3152 10 313.2735 346.9473 364.9576 393.2091 309.0004 322.1607328.1112 355.1110 373.9307 385.1689 397.1351 0 300 310 320 330 340 350 360 370 380 390 400 m /z S-12
Relative Abundance Figure S8. HRMS (ESI) spectra of ALF probe in Methanol 5_- #247 RT: 3.42 AV: 1 NL: 3.04E6 T: FTMS - c ESI Full ms [900.00-1200.00] 100 1100.2881 90 80 70 60 1102.2853 50 40 1103. 2886 30 20 1080.3448 1177.3969 10 1065.2415 1167.4138 1026.3190 1137.4053 1199.3473 915.3920 934.1876 951.4125 992.3351 1048.4110 1008.3080 1124.2793 0 900 920 940 960 980 1000 1020 1040 1060 1080 1100 1120 1140 1160 1180 1200 m/z S-13
Figure S9. (a) Fluorescence peak intensities (λ em = 520 nm) of 10 μm ALF probe to caspase-8 of varying concentrations. (b) A linear dependency was obtained between the fluorescence response and caspase-8 concentration in the range from 30 pm to 3 nm. The regression equation was Y = 642.0751 [caspase-8] + 287.6823 with a linear coefficient R of 0.9987. Higher caspase-8 concentration gave nonlinearly increased fluorescence responses, and saturated fluorescence response was ~2200 with 3 nm caspase-8. Data were repeated three times, and the error bars represent standard deviations. λ ex/em = 360/520 nm. S-14
Figure S10. Lineweaver-Burk double reciprocal plot for the enzyme-catalyzed reaction. The Michaelis-Menten equation was described as: V = V max [probe] / (K m + [probe]), where V is the reaction rate, [probe] is ALF probe concentration (substrate), and K m is the Michaelis constant. Conditions: 2.4 nm caspase-8, 1-20 μm ALF probe. All measurements were performed at 37 C, λ ex/em = 360/520 nm. Reaction at each probe concentration was repeated three times, and the error bars represent standard deviations. Points were fitted using a linear regression model (correlation coefficient R = 0.998). S-15
Figure S11. UV-vis absorption spectra of 10 μm ALF probe (black line), 10 μm CHCQ (blue line) and the reaction mixture of ALF probe and 3 nm caspase-8 (red line) at 37 C. The inset is photos for the probe (left side) and CHCQ product from the reaction mixture (right side), A: under room light; B: under light of 365 nm. S-16
Figure S12. The photos of TLC plate under different light used to compare ALF probe, the reference sample of CHCQ and the reaction product from the reaction of ALF probe with caspase-8. (A) under room light; (B) under light of 365 nm. Spots on the TLC plate are: a. ALF probe; b. the mixture of a, c and d; c. the reaction product of ALF probe and caspase-8; d. CHCQ. The eluent for TLC: petroleum ether/ethyl acetate = 3/1 (v/v). S-17
Figure S13. Effect of ph on the fluorescence intensity of 10 μm ALF probe reacted with 3 nm caspasse-8 at 37 C. Reaction at each ph value was repeated three times, and the error bars represent standard deviations. λ ex/em = 360/520 nm S-18
Figure S14. Effect of temperature on the fluorescence intensity of 10 μm ALF probe reacted with 3 nm caspasse-8. Reaction at each temperature was repeated three times, and the error bars represent standard deviations. λ ex/em = 360/520 nm. S-19
Figure S15. Cytotoxicity assay for HeLa cells. Cells incubated with ALF probe for 6 h. Data were reported as the mean ± standard deviation of triplicate experiments. S-20
Figure S16. 3D confocal imaging of HeLa cells with 3 μm ALF probe. (a) Cellular imaging at different sections through the z-axis which were acquired at 1-μm z-axis intervals; (b) Projection mapping on the x-y plane of data acquired at 1-μm z-axis intervals. Scale bar = 20 µm. (a) (b) S-21
Figure S17. Effect of MMC on the caspase-8 levels in HeLa cells. Confocal fluorescence images of HeLa cells that were pretreated with 3 μm ALF probe for 30 min and then treated with varying concentrations of MMC (0, 10, 20, 40, and 60 μg/ml) for 60 min at 37 C. Scale bar = 20 µm. 0 μg/ml 10 μg/ml 20 μg/ml 40 μg/ml 60 μg/ml S-22