The halobacterial phototaxis receptors sensory rhodopsin I and II (SRI, SRII) enable the bacteria to seek optimal light conditions for ion pumping by bacteriorhodopsin and/or halorhodopsin. The incoming signal is transferred across the plasma membrane by means of receptor-specific transducer proteins that bind tightly to their corresponding photoreceptors. To investigate the receptor/transducer...

The excited states of the three retinal proteins, bovine rhodopsin (Rh), bacteriorhodopsin (bR), and sensory rhodopsin II (sRII) were studied using the symmetry-adapted cluster-configuration interaction (SAC-CI) and combined quantum mechanical and molecular mechanical (QM/MM) methods. The computed absorption energies are in good agreement with the experimental ones for all three proteins. The s...

The first steps in the photocycles of the archaeal photoreceptor proteins sensory rhodopsin (SR) I and II from Halobacterium salinarum and SRII from Natronobacterium pharaonis have been studied by ultrafast pump/probe spectroscopy and steady-state fluorescence spectroscopy. The data for both species of the blue-light receptor SRII suggests that their primary reactions are nearly analogous with ...

The mechanism of color tuning in the rhodopsin family of proteins has been studied by comparing the optical properties of the light-driven proton pump bacteriorhodopsin (bR) and the light detector sensory rhodopsin II (sRII). Despite a high structural similarity, the maximal absorption is blue-shifted from 568 nm in bR to 497 nm in sRII. The molecular mechanism of this shift is still a matter o...

Sensory rhodopsin II (SRII, also called pharaonis phoborhodopsin, ppR) is responsible for negative phototaxis in Natronomonas pharaonis. Photoisomerization of the retinal chromophore from all- trans to 13- cis initiates conformational changes in the protein, leading to activation of the cognate transducer protein (HtrII). We previously observed enhancement of the C 14-D stretching vibration of ...

Rhodopsins possess retinal chromophore surrounded by seven transmembrane α-helices, are widespread in prokaryotes and in eukaryotes, and can be utilized as optogenetic tools. Although rhodopsins work as distinctly different photoreceptors in various organisms, they can be roughly divided according to their two basic functions, light-energy conversion and light-signal transduction. In microbes, ...

Increasing researches suggest that inflammatory response is involved in vascular remodeling, which plays an important role in the development of aortic dissection. Glucocorticoids have been widely used in the clinical practice due to its powerful and effective anti-inflammatory property. However, the potential relationship between glucocorticoids and aortic dissection was still obscure. This st...

Norovirus (NV) is a major viral pathogen that causes nonbacterial acute gastroenteritis and outbreaks of food-borne disease. The genotype of NV most frequently responsible for NV outbreaks is GII.4, which accounts for 60-80% of cases. Moreover, original and new NV variant types have been continuously emerging, and their emergence is related to the recent global increase in NV infection. In this...