• Korean Journal of Animal Reproduction
• /
• v.18 no.3
• /
• pp.191-197
• /
• 1994

It is generally known that mutations in any of several genes encoding photoreceptor-specific proteins have resulted in retinitis pigmentosa (RP), a disease characterized by losing photoreceptor function with progressive degeneration of photoreceptor cells and eventually leading to blindness. To study the procure and cure of photoreceptor degeneration, we produced transgenic mice. Transgene consisted of a 12.5kb genomic DNA fragment that contains mutated pig rhodopsin gene (Pro-347-Ser) including both the 5'-franking (4.0 kb) and the 3'-franking (2.9 kb) sequences. This gene was used for the production of transgenic mouse. The mutated rhodopsin DNA was microinjected into male pronuclei of fertilized mouse (C57BL /6]) embryos. We detected transgenic animals harboring mutated rhodopsin gene by PCR and Southern blot analysis. These transgenic mice showed stable transmission of microinjected rhodopsin gene into their offspring. Therefore these animals will provide a novel approach to study the mechanism of the photoreceptor degeneration and be provided as a disease model for the treatment of the blind in human.

• Clean Technology
• /
• v.17 no.3
• /
• pp.280-282
• /
• 2011

Capture and conversion of abundant solar energy using biotechnology will be essential for the development of sustainable and future energy. Photosynthesis is used for the production of biofuels such as biohydrogen. In this study, lightharvesting xanthorhodopsin consisting of retinal and salinixanthin was isolated from a photosynthetic microorganism Salinibacter ruber by aqueous two phase extraction. To stabilize the light-harvesting machine, artificial xanthorhodopsin-liposome system was reconstructed to have photoelectron absorption activity.

• Journal of Life Science
• /
• v.17 no.6 s.86
• /
• pp.783-790
• /
• 2007

G protein coupled receptors (GPCRs) transmit various extracellular signals into the cells. Upon binding of the ligands, conformational changes in the extracellular and/or transmembrane (TM) domains of CPCRs were propagated into the cytoplasmic (CP) domain of the molecule leading to the activation of their cognate heterotrimeric C proteins and kinases. Constitutively active GPCR mutants causing the activation of C Protein signaling even in the absence of ligand binding are of interest for the study of activation mechanism of GPCRs. Two classes of constitutively active mutations, categorized by their effects on the salt bridge between Ell3 and K296, were found in the TM domain of rhodopsin. Opsin mutants containing combinations of the mutations were constructed to study the conformational changes required for the activation of rhodopsin. Rhodopsin chromophore regenerated with 11-cis-retinal showed a thermal stability inversely correlated with its constitutive activity. In contrast, rhodopsin mutants exhibited a binding affinity to an agonist, all-trans-retinal, in a constitutive activity-dependent manner. In order to test whether the conformational changes responsible for the activation of trans-ducin (Gt) are the same as the conformation required for the recognition of rhodopsin kinase, analysis of the mutants were carried out with phosphorylation by rhodopsin kinase. Rhodopsin mutants containing combinations of different classes of the mutations showed a strong synergistic effect on the phosphorylation of the mutants in the dark as similar to that of Gt activation. The results suggest that at least two or three kinds of segmental and independent conformational changes are required for the activation of rhodopsin and the conformational changes responsible for activating rhodopsin kinase and Gt are similar to each other.

• Journal of Life Science
• /
• v.22 no.7
• /
• pp.863-870
• /
• 2012

Rhodopsin, a dim light photoreceptor, has been regarded as one of the model systems for the structural and functional study of G protein-coupled receptors (GPCRs). Constitutively active mutant GPCRs leading to the activation of heterotrimeric GDP/GTP-binding protein signaling in the absence of ligand binding are of interest for the study of the activation mechanism in GPCRs. The present study focused on the opsin mutant E134Q/M257Y, which showed a moderate level of constitutive activity and the formation of two distinct rhodopsin chromophores with absorption maxima of 500 nm and 380 nm, depending on the presence of an inverse agonist, 11-cis-retinal, and an agonist, all-trans-retinal, respectively. Reconstitution of the mutant rhodopsin upon incubation with different ratios of 11-cis-retinal and the all-trans-retinal, as well as upon sequential binding of the two retinals, indicated its preferential binding to 11-cis-retinal. The thermal stability of the 11-cis-retinal-bound form of the E134Q/M257Y mutant was lower than that of the mutants containing a single replacement but higher than that of the all-trans-retinal-bound forms. The mutant also showed a lower stability in its opsin state as compared with that of the wild-type opsin but had little effects on the binding affinity to 11-cis-retinal. Information obtained in this study will be helpful for analyzing the structural changes associated with the activation of rhodopsin and GPCRs.

• Korean Journal of Microbiology
• /
• v.47 no.1
• /
• pp.22-29
• /
• 2011

Rhodopsin is a membrane protein with seven transmembrane region which contains a retinal as its chromophore. Although there have been recently reports on various photo-biochemical features of rhodopsins by a wide range of purifying and measurement methods, there was no actual comparison related to the difference of biochemical characteristics according to their physical environment of rhodopsins. First, proteorhodopsin (PR) was found in marine proteobacteria whose function is known for pumping proton using light energy. Second one is Anabaena sensory rhodopsin (Nostoc sp.) PCC7120 (ASR) which belongs to eubacteria acts as sensory regulator since it is co-expressed with transducer 14 kDa in an operon. In this study, we applied two types of rhodopsins (PR and ASR) to various environmental conditions such as in Escherichia coli membranes, membrane in acrylamide gel, in DDM (n-dodecyl-${\beta}$-D-maltopyranoside), OG (octyl-${\beta}$-D-glucopyranoside), and reconstituted with DOPC (1,2-didecanoyl-sn-glycero-3-phosphocholine). According to the light-induced difference spectroscopy, rhodopsins in 0.02% DDM clearly showed photointermediates like M, and O states which respond to the different wavelengths, respectively and showed the best signal/noise ratio. The laser-induced difference spectra showed the fast formation and decay rate of photointermediates in the DDM solubilized samples than gel encapsulated rhodopsin. Each of rhodopsins seemed to be adapted to its surrounding environment.

• Proceedings of the Optical Society of Korea Conference
• /
• 2000.02a
• /
• pp.114-115
• /
• 2000

Halobacterium halobium에서 추출한 Bacteriorhodopsin(bR)을 고분자 물질에 첨가해 박막화하였다. 이 단백질 박막 소자의 photodynamic특성을 이용하여 광 switching system을 구성하였다. 광 switch system은 pump광을 이용해 B상태와 M상태에서 축퇴4광파 혼합방식으로 구성했다. Red, blue, violet 광원을 사용하여 B상태와 M상태 격자를 형성하고 on-off되는 위상공액신호를 측정했다. (중략)

• KSBB Journal
• /
• v.13 no.3
• /
• pp.268-271
• /
• 1998

Bacteriorhodopsin in the purple membrane (PM) of halobacteria has recently been attracting much attention to be used as a component of molecular electron device and optical computers. In order to increase the productivity of bacteriorhodopsin in high cell density cultures of Halobacterium halobium R1, an internal membrane cell-retention bioreactor system was employed. As a result, the production of cell mass at OD660 of 12 and of bacteriorhodopsin at 125-130 mg/L were obtained using the internal membrane bioreactor system at a dilution rate of 0.066 hr-1. The productivity achieved by the internal membrane system (0.7 mg/L$.$hr) was 3.5-fold higher than that obtained by the corresponding batch cultivations (0.2 mg/L$.$hr).

• Journal of Korean Ophthalmic Optics Society
• /
• v.21 no.1
• /
• pp.69-76
• /
• 2016

Purpose: The study was conducted to determine that photoreceptors of mouse having pigment in RPE(retinal pigment epithelium) can be damaged by blue-light and apoptosis of specific cells among photoreceptors are induced by blue-light, and to assist the investigation of AMD(Age-related macular degeneration) mechanisms and development of AMD drugs. Methods: C57Black mice were injured by irradiating $2800{\pm}10lux$ of 463 nm LED for 6 hours after 24 hours dark adaptation and eyes were enucleated 1, 3, 7 days. Damage of retina induced by blue-light was determined by western blotting GFAP(Glial fibrillary acidic protein) expression. In the light-injured retina, cell death of photoreceptors was determined by TUNEL(Terminal deoxynucleotidyl transferase dUTP nick end labeling) assay. ERK(Extracellular signal-regulated kinases), JNK, and SRC(sarcoma) expression were assessed by western blotting to determine regulated pathway. Blue light-injured retina were immunostained with antibodies against Opsin and Rhodopsin as markers of photoreceptors to compared the damage cone cells with rod cells. Results: After 1, 3 and 7 days from exposure to blue-light, thickness of retina was more decreased than control, and more decreased at nuclear layer than at outer plexiform layer and GFAP expression was increased day 1 after blue-light injured. While phosphorylated ERK and SRC protein expressions at day 1 were increased after blue-light injured, phosphorylated c-JUN was decreased. Fluorescence intensity analysis showed that markers of cone and rod cells were decreased after blue-light injured and Opsin was more decreased than Rhodopsin. Conclusions: The study suggests possibilities that the blue-light promotes retinal damage and causes apoptotic cell death via ERK and SRC pathway in mouse retina, and blue-light retinal damage is more induced cone cells apoptosis than rod cells directly.

• Korean Journal of Optics and Photonics
• /
• v.13 no.5
• /
• pp.414-420
• /
• 2002

We realized optical logic gates using a bacteriorhodopsin (bR) doped polymer film. The bR undergoes a complex photocycle characterized by several spectroscopically distinct intermediate states. We realized optical logic gates using a He-Ne laser (632.8 nm) and a He-Cd laser (413 nm) that consider B-state and absorption change of M-state in the photocycle of bR. Also, we realized high speed AND logic gate using He-Ne laser (632.8 nm) and the second harmonics at 532 nm from a pulsed Nd-YAG laser that considering absorption spectrum between B-state and K-state.

• Korean Journal of Microbiology
• /
• v.54 no.4
• /
• pp.460-462
• /
• 2018

Flagellimonas eckloniae DOKDO $007^T$, isolated from the rhizosphere of the marine algae Ecklonia kurome collected from Dokdo Island, South Korea, is a marine Flavobacteria belonging to the family Flavobacteriaceae. The genome consists of 4,132,279 bp, 3,527 coding sequences with 37.85% G + C contents and two contigs in one scaffold chromosome. This strain contains a gene encoding proteorhodopsin, as well as other retinal biosynthesis genes, allowing it to utilize sunlight as an energy source. The strain contained only few segment of flagellar constructing gene cluster and this is not consistent with genus name Flagellimonas, therefore, revision of the genus name is required.