Related Experiment Video
Updated: Jul 25, 2026

Crystallization of Membrane Proteins in Lipidic Mesophases
Published on: March 28, 2011
Crystals of the carotenoid protein from Arthrospira maxima containing uniformly oriented pigment molecules
1UCLA-DOE Laboratory of Structural Biology and Molecular Medicine, 90095-1570, USA.
Abstract:
Crystals of a carotenoid protein from the cyanobacterium Arthrospira maxima have been grown in space group C2 with unit-cell dimensions a = 219.6, b = 40.3, c = 75.5 A and beta = 95.5 degrees. The crystals diffract X-rays to 2.3 A resolution and display unusual optical properties in polarized light that suggest that all of the carotenoid molecules in the crystals are oriented similarly. A slight increase in the concentration of a crystallization additive in the mother liquor induces macroscopic twinning, which is also visible when the crystals are illuminated with polarized light.
Related Concept Videos
The Antenna Complex
Photosystems
Functioning of Photosystems
Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
Channel Rhodopsins
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
IR and UV–Vis Spectroscopy of Carboxylic Acids
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency, 1710 cm−1. The C=O bond of the...
Spectroscopy of Carboxylic Acid Derivatives
In the...
Red Algae

