INTRODUCTION .............................................................. 682 PURPLE MEMBRANE ....................................................... 683 BACTEBRIORHODOPSIN: A LIGHT-DRIVEN PUMP FOR PROTONS ..... ..... 686 SECONDARY GRADIENTS: TRANSMEMBRANE MOVEMENTS OF Na+, K', AND Cl................................................................... 689 AMINO ACID TRANSPORT ............... ....

Bauhinia variegata, "PURPLE ORCHID TREE" Spectacular, deciduous tree w/ light green, 2-lobed leaves & 3-in. purple, orchidlike flowers in late winter/early spring (a few may have white flowers). [11] (H*) Caesalpinia mexicana , "MEXICAN BIRD-OF-PARADISE" Heatloving, small tree or large shrub w/ ferny, blue-green leaves & showy clusters of lemon yellow flowers throughout warm weather; needs good...

Two bilayer metal-organic frameworks (MOFs) respectively containing trinuclear Pb/K and Cd/Na clusters have been solvothermally synthesized. Photoluminescence studies showed that they exhibit tunable purple-to-red-to-green and purple-to-green luminescence behaviours by variation of excitation light, respectively.

Current-voltage (I-V) characteristics in proteins are sensitive to conformational changes induced by an external stimulus (photons, chemical, etc.). This sensitivity can be used in medical and industrial applications as well as shedding new light on the microscopic structure of biological materials. Here, we show that a sequential tunneling model of carrier transfer between neighboring amino ac...

Purple membrane (lambda max = 568 nm) can be converted to blue membrane (lambda max = 605 nm) by either acid titration or deionization. Partially delipidated purple membrane, containing only 25% of the initial lipid phosphorus, could be converted to a blue form by acid titration but not by deionization. This reversible transition of delipidated membrane did not require the presence of other cat...

Mid-infrared spectroscopy is a widely used tool for material identification and secondary structure analysis in chemistry, biology and biochemistry. However, the diffraction limit prevents nanoscale protein studies. Here we introduce mapping of protein structure with 30 nm lateral resolution and sensitivity to individual protein complexes by Fourier transform infrared nanospectroscopy (nano-FTI...

We have used high-speed atomic force microscopy to study the dynamics of bacteriorhodopsin (bR) molecules at the free interface of the crystalline phase that occurs naturally in purple membrane. Our results reveal temporal fluctuations at the crystal edges arising from the association and dissociation of bR molecules, most predominantly pre-formed trimers. Analysis of the dissociation kinetics ...

A new spectral species of the purple membrane of Halobacterium halobium has been observed below pH 3.2. The formation of this new species is temperature-dependent and is favoured by increasing temperature up to the physiological range of the organism. The rate of formation at pH 3.0 and 22 degrees C is 7.9 x 10-3s-1. The spectral distribution and temperature-dependence of the new species sugges...