| Literature DB >> 32367573 |
Nobuo Kitada1,2, Ryohei Saito1,3, Rika Obata1, Satoshi Iwano4, Kazuma Karube1, Atsushi Miyawaki4, Takashi Hirano1, Shojiro A Maki1,2.
Abstract
Interestingly, only the D-form of firefly luciferin produces light by luciferin-luciferase (L-L) reaction. Certain firefly luciferin analogues with modified structures maintain bioluminescence (BL) activity; however, all L-form luciferin analogues show no BL activity. To this date, our group has developed luciferin analogues with moderate BL activity that produce light of various wavelengths. For in vivo bioluminescence imaging, one of the important factors for detection sensitivity is tissue permeability of the number of photons emitted by L-L reaction, and the wavelengths of light in the near-infrared (NIR) range (700-900 nm) are most appropriate for the purpose. Some NIR luciferin analogues by us had performance for in vivo experiments to make it possible to detect photons from deep target tissues in mice with high sensitivity, whereas only a few of them can produce NIR light by the L-L reactions with wild-type luciferase and/or mutant luciferase. Based on the structure-activity relationships, we designed and synthesized here a luciferin analogue with the 5-allyl-6-dimethylamino-2-naphthylethenyl moiety. This analogue exhibited NIR BL emissions with wild-type luciferase (λmax = 705 nm) and mutant luciferase AlaLuc (λmax = 655 nm).Entities:
Keywords: Akaluc; Photinus pyralis luciferase; TokeOni; luciferin analogues; luciferin-luciferase reaction; mutant luciferase; near-infrared bioluminescence
Mesh:
Substances:
Year: 2020 PMID: 32367573 PMCID: PMC7383472 DOI: 10.1002/chir.23236
Source DB: PubMed Journal: Chirality ISSN: 0899-0042 Impact factor: 2.437
FIGURE 1Structures of firefly luciferin (1), TokeOni (2), and designed luciferin analogue 3 [Correction added on 5 June 2020, after first online publication: The figure 1 image has been corrected.]
FIGURE 2Structure–BL activity relationships for luciferin analogues. Analogues 2, 4, and 5 were previously reported ,
SCHEME 1Synthetic routes for luciferin analogue 3. A, NBS, DMSO, r.t.; B, NaBH3CN, formaldehyde, CH3COOH, CH3OH, 0°C to r.t.; C, Allyltributyltin, Pd (PPh3)2Cl2, LiCl, DMF, 90°C; D, DIBAL‐H, toluene, 0°C to r.t.; E, DMP, pyridine, CH2Cl2, 0°C to r.t.; F, Ph3PCHCOOEt, toluene, r.t.; G, NaOH aq., iPrOH, reflux; H, ‐Cys (Trt)‐OMe, DMT‐MM, DMF, r.t.; I, Tf2O, CH2Cl2, 0 °C; J, HCl aq., THF, r.t
Bioluminescence and chemiluminescence properties of 1–3 and 5
| Compound | Rel. Int. |
|
|
|
|---|---|---|---|---|
|
| 100% | 570 | 610 | 595 |
|
| 10% | 675 | 660 | 685 |
|
| 1.3% | 705 | 665 | 685 |
|
| 0.8% | 690 | 660 | 620 |
Relative light intensity at λ BL upon reaction with Ppy luciferase for the L–L reactions of 3 during the initial 600 s compared with that of 1.
Bioluminescence emission maximum upon reaction with Ppy luciferase.
Bioluminescence emission maximum upon reaction with mutant luciferase Akaluc.
Chemiluminescence emission maximum.
FIGURE 3The bioluminescence spectra of 1–3 and 5 reacted with Ppy luciferase A, and Akaluc B, respectively
FIGURE 4The most stable optimized structures of the luciferin forms 3 and 5 and optimized structures of the oxyluciferin forms oxy‐3 and oxy‐5(phenolate) having the conformations corresponding to the structures of 3 and 5
Time‐dependent density functional theory calculation data for oxy‐2, oxy‐3, and oxy‐5
| Compound | Transition |
|
| Configuration |
|---|---|---|---|---|
|
| S0 → S1 | 2.82 | 439 (1.38) | H → L (0.70) |
|
| S0 → S1 | 2.85 | 435 (0.58) | H → L (0.70) |
|
| S0 → S1 | 2.40 | 516 (1.23) | H → L (0.71) H ← L (−0.14) |
|
| S0 → S2 | 2.67 | 464 (0.87) | H → L + 1 (0.70) |
The allowed transition to the excited singlet state with the lowest excitation energy (S0 → S1 or S0 → S2).
Vertical excitation energy for the transition.
Wavelength (λ ex) estimated from the transition energy. Oscillator strength (f) is in the parenthesis.
Configuration of excitation. Coefficient is in the parenthesis. H, L, and L + 1 denote highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), and LUMO+1, respectively.
Kiyama et al.