Rhodopsin is currently the only available atomic-resolution template for understanding biological functions of the G protein-coupled receptor (GPCR) family. The structural basis for the phenomenal dark state stability of 11-cis-retinal bound to rhodopsin and its ultrafast photoreaction are active topics of research. In particular, the beta-ionone ring of the retinylidene inverse agonist is cruc...

We have used suction electrode recording together with rapid steps into 0.5 mM IBMX solution to investigate changes in guanylyl cyclase velocity produced by pigment bleaching in isolated cones of the salamander Ambystoma tigrinum. Both backgrounds and bleaches accelerate the time course of current increase during steps into IBMX. We interpret this as evidence that the velocity of the guanylyl c...

Investigation of the chemical composition of the essential oils from subterranean organs (S) of Nephrolepis cordifolia (NC) and Nephrolepis exaltata (NE) (F. Lomariopsidaceae) grown in Egypt was carried out. Gas Chromatography/mass Spectrometry (GC/MS) analysis of the hydro-distilled NCS and NES oils revealed that oxygenated compounds were abundant, being 55.35% and 33.85%, respectively. Ethyl ...

1. beta-Ionone vapour has been shown to cause an increase in the more saturated carotenes and a decrease in the less saturated carotenes of Rhodotorula glutinis. Lycopersene (dihydrophytoene) has been proposed as a precursor to phytoene. Attempts were made to isolate lycopersene from beta-ionone-treated cultures of R. glutinis. 2. Large samples of beta-ionone-treated cultures were examined for ...

Chemosensory proteins (CSPs) play important roles in chemical communication by insects, as they recognize and transport environmental chemical signals to receptors within sensilla. In this study, we identified HoblCSP1 and HoblCSP2 from a cDNA library of Holotrichia oblita antennae, successfully expressed them in E. coli and purified them by Ni ion affinity chromatography. We then measured the ...

We report the formation of trihalomethanes and other disinfection by-products from four polyfunctional terpenoids during simulated chlorination of natural waters. Complex suites of products were identified by closed loop stripping analysis (CLSA)/gas chromatography-mass spectrometry (GC-MS) from halogenation of beta-carotene and retinol. beta-Ionone appeared to be a key intermediate in the halo...

A crystal structure of the lutein-binding domain of human StARD3 (StAR-related lipid-transfer protein 3; also known as MLN64) has been refined to 1.74 Å resolution. A previous structure of the same protein determined to 2.2 Å resolution highlighted homology with StARD1 and shared cholesterol-binding character. StARD3 has since been recognized as a carotenoid-binding protein in the primate retin...

The pathway of carotene biosynthesis from isopentenyl pyrophosphate in tomato fruit plastids has been established, except for minor details, through the conversion of radioactive sub— strates and intermediates to acyclic and cyclic carotenes in cell—free systems. After the pathway of carotene biosynthesis was established attention was turned to the isola— tion and purification of enzymes of car...