scholarly journals Fluorescence Properties of a Novel Cyanobacteriochrome GAF Domain from Spirulina that Exhibits Moderate Dark Reversion

2018 ◽  
Vol 19 (8) ◽  
pp. 2253 ◽  
Author(s):  
Xian-Jun Wu ◽  
Hong Yang ◽  
Yi Sheng ◽  
Yong-Li Zhu ◽  
Ping-Ping Li
Keyword(s):  
Quantum Yield ◽  
Light Intensity ◽  
Fluorescence Quantum Yield ◽  
Fluorescent Protein ◽  
Red Light ◽  
Wild Type ◽  
Fluorescent Properties ◽  
Dark State ◽  
Dark Reversion ◽  
Spirulina Subsalsa

Cyanobacteriochromes (CBCRs) are biliproteins for photoreception that are present in cyanobacteria. These proteins possess one or more unique cGMP-specific phosphodiesterase/adenylate cyclase/FhlA (GAF) domains that can covalently bind the linear tetrapyrrole (bilin). Light absorption triggers the photoisomerization of bilin between the 15Z and 15E photostates. The 15E photoproduct of some CBCR GAF domains can revert to the stable 15Z state in the absence of light. In some cases, this property makes these domains function as sensors of light intensity or as red/dark optogenetic switches. However, there have been few reports regarding the applicability of these fluorescent properties. Here, we report a red/green cyanobacteriochrome GAF domain from Spirulina subsalsa, designated SPI1085g3, which exhibited photoconversion from the red-absorbing dark state (Pr, λmax = 642 nm) to the orange-absorbing photoproduct state (Po, λmax = 590 nm), and exhibited moderate dark reversion (t1/2 = 3.3 min) from the Po state to the Pr state. The SPI1085g3 Pr state exhibited intense red fluorescence (λmax = 662 nm), with a quantum yield of 0.14. The fluorescence was switched off by red light irradiation and increased in the dark. Replacement of Cys448 of SPI1085g3 with Ser resulted in a slightly improved fluorescence quantum yield and nearly 13-fold faster dark reversion (t1/2 = 15.2 s) than that of the wild type. This novel red/dark-switchable fluorescent biliprotein expands the present repertoire and diversity of photoswitchable fluorescent protein candidates.

Dramatic reduction in fluorescence quantum yield in mutants of Green Fluorescent Protein due to fast internal conversion

1998 ◽  
Vol 237 (1-2) ◽  
pp. 183-193 ◽  
Author(s):  
Andreas D Kummer ◽  
Christian Kompa ◽  
Harald Lossau ◽  
Florian Pöllinger-Dammer ◽  
Maria E Michel-Beyerle ◽  
...  
Keyword(s):  
Green Fluorescent Protein ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Internal Conversion ◽  
Fluorescent Protein ◽  
Dramatic Reduction ◽  
Green Fluorescent

Fluorescence Enhancement of a Microbial Rhodopsin via Electronic Reprogramming

2018 ◽  
Author(s):  
Maria del Carmen Marin ◽  
Damianos Agathangelou ◽  
Yoelvis Orozco-González ◽  
Alessio Valentini ◽  
Yoshitaka Kato ◽  
...  
Keyword(s):  
Excited State ◽  
Quantum Yield ◽  
Excited States ◽  
Fluorescence Quantum Yield ◽  
Fluorescence Enhancement ◽  
Energy Surface ◽  
Wild Type ◽  
Excited State Lifetime ◽  
State Potential ◽  
Microbial Rhodopsin

The manuscript reports on two mutations of the photo-sensory protein Anabaena Sensory Rhodopsin and how these mutations modify the fluorescence quantum yield with respect to the wild-type protein. Experimental results are presented and explained theoretically on the basis of mixing of the S1 and S2 excited states. This mixing modulated by electrostatic and steric effects, tunes the excited state potential energy surface, and thereby the excited state lifetime and the fluorescence quantum yield.<br>

scholarly journals Designing Red-Shifted Molecular Emitters Based on the Annulated Locked GFP Chromophore Derivatives

2021 ◽  
Vol 22 (24) ◽  
pp. 13645
Author(s):  
Gregory D. Sinenko ◽  
Dilara A. Farkhutdinova ◽  
Ivan N. Myasnyanko ◽  
Nadezhda S. Baleeva ◽  
Mikhail S. Baranov ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Red Light ◽  
Conjugation Length ◽  
Fluorescent Properties ◽  
Promising Strategy ◽  
Quantum Chemistry Calculations ◽  
Polycyclic Aromatic ◽  
Gfp Chromophore ◽  
Green Fluorescent ◽  
High Level

Bioimaging techniques require development of a wide variety of fluorescent probes that absorb and emit red light. One way to shift absorption and emission of a chromophore to longer wavelengths is to modify its chemical structure by adding polycyclic aromatic hydrocarbon (PAH) fragments, thus increasing the conjugation length of a molecule while maintaining its rigidity. Here, we consider four novel classes of conformationally locked Green Fluorescent Protein (GFP) chromophore derivatives obtained by extending their aromatic systems in different directions. Using high-level ab initio quantum chemistry calculations, we show that the alteration of their electronic structure upon annulation may unexpectedly result in a drastic change of their fluorescent properties. A flip of optically bright and dark electronic states is most prominent in the symmetric fluorene-based derivative. The presence of a completely dark lowest-lying excited state is supported by the experimentally measured extremely low fluorescence quantum yield of the newly synthesized compound. Importantly, one of the asymmetric modes of annulation provides a very promising strategy for developing red-shifted molecular emitters with an absorption wavelength of ∼600 nm, having no significant impact on the character of the bright S-S1 transition.

Fluorescence Enhancement of a Microbial Rhodopsin via Electronic Reprogramming

2018 ◽  
Author(s):  
Damianos Agathangelou ◽  
Yoelvis Orozco-González ◽  
Alessio Valentini ◽  
Yoshitaka Kato ◽  
Rei Abe-Yoshizumi ◽  
...  
Keyword(s):  
Excited State ◽  
Quantum Yield ◽  
Excited States ◽  
Fluorescence Quantum Yield ◽  
Fluorescence Enhancement ◽  
Energy Surface ◽  
Wild Type ◽  
Excited State Lifetime ◽  
State Potential ◽  
Microbial Rhodopsin

The manuscript reports on two mutations of the photo-sensory protein Anabaena Sensory Rhodopsin and how these mutations modify the fluorescence quantum yield with respect to the wild-type protein. Experimental results are presented and explained theoretically on the basis of mixing of the S1 and S2 excited states. This mixing modulated by electrostatic and steric effects, tunes the excited state potential energy surface, and thereby the excited state lifetime and the fluorescence quantum yield.<br>

Fluorescence Enhancement of a Microbial Rhodopsin via Electronic Reprogramming

2018 ◽  
Author(s):  
Maria del Carmen Marin ◽  
Damianos Agathangelou ◽  
Yoelvis Orozco-González ◽  
Alessio Valentini ◽  
Yoshitaka Kato ◽  
...  
Keyword(s):  
Excited State ◽  
Quantum Yield ◽  
Excited States ◽  
Fluorescence Quantum Yield ◽  
Fluorescence Enhancement ◽  
Energy Surface ◽  
Wild Type ◽  
Excited State Lifetime ◽  
State Potential ◽  
Microbial Rhodopsin

The manuscript reports on two mutations of the photo-sensory protein Anabaena Sensory Rhodopsin and how these mutations modify the fluorescence quantum yield with respect to the wild-type protein. Experimental results are presented and explained theoretically on the basis of mixing of the S1 and S2 excited states. This mixing modulated by electrostatic and steric effects, tunes the excited state potential energy surface, and thereby the excited state lifetime and the fluorescence quantum yield.<br>

Postnatal growth rate and gonadal development in circadian tau mutant hamsters reared in constant dim red light

Reproduction ◽  
2000 ◽  
pp. 327-330 ◽  
Author(s):  
RJ Lucas ◽  
JA Stirland ◽  
YN Mohammad ◽  
AS Loudon
Keyword(s):  
Time Course ◽  
Red Light ◽  
Somatic Growth ◽  
Postnatal Growth ◽  
Gonadal Development ◽  
Testicular Development ◽  
Wild Type ◽  
Similar Time ◽  
Syrian Hamsters ◽  
Body Weights

The role of the circadian clock in the reproductive development of Syrian hamsters (Mesocricetus auratus was examined in wild type and circadian tau mutant hamsters reared from birth to 26 weeks of age under constant dim red light. Testis diameter and body weights were determined at weekly intervals in male hamsters from 4 weeks of age. In both genotypes, testicular development, subsequent regression and recrudescence exhibited a similar time course. The age at which animals displayed reproductive photosensitivity, as exhibited by testicular regression, was unrelated to circadian genotype (mean +/- SEM: 54 +/- 3 days for wild type and 59 +/- 5 days for tau mutants). In contrast, our studies revealed a significant impact of the mutation on somatic growth, such that tau mutants weighed 18% less than wild types at the end of the experiment. Our study reveals that the juvenile onset of reproductive photoperiodism in Syrian hamsters is not timed by the circadian system.

scholarly journals Synthesis of carbon nitride oligomer as a precursor of melon with improved fluorescence quantum yield

2021 ◽  
Vol 2 (18) ◽  
pp. 6083-6093
Author(s):  
Yuto Miyake ◽  
Goichiro Seo ◽  
Kotaro Matsuhashi ◽  
Noriyuki Takada ◽  
Kaname Kanai
Keyword(s):  
Optical Properties ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Carbon Nitride

Melem tetramer, the newly synthesized carbon nitride compound is composed of oligomers with four melem units, is stable in air, and has improved optical properties compared to melon.

Effects of electron-withdrawing groups in imidazole-phenanthroline ligands and their influence on the photophysical properties of EuIII complexes for white light-emitting diodes

2017 ◽  
Vol 41 (18) ◽  
pp. 9826-9839 ◽  
Author(s):  
Boddula Rajamouli ◽  
Rachna Devi ◽  
Abhijeet Mohanty ◽  
Venkata Krishnan ◽  
Sivakumar Vaidyanathan
Keyword(s):  
Thin Film ◽  
Quantum Yield ◽  
White Light ◽  
Light Emitting Diode ◽  
Photophysical Properties ◽  
Red Light ◽  
Europium Complexes ◽  
Light Emitting ◽  
White Light Emitting Diodes ◽  
Phenanthroline Ligands

The red light emitting diode (LED) was fabricated by using europium complexes with InGaN LED (395 nm) and shown digital images, corresponding CIE color coordinates (red region) as well as obtained highest quantum yield of the thin film (78.7%).

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