Related Experiment Video
Updated: Aug 15, 2026
Crystallization of Membrane Proteins in Lipidic Mesophases
Published on: March 28, 2011
Two different crystal forms of sorcin, a penta-EF-hand Ca2+-binding protein
V Nastopoulos1, A Ilari, G Colotti
1Department of Chemistry, University of Patras, 265 00 Patras, Greece.
Abstract:
Sorcin is a 198 amino-acid Ca(2+)-binding protein that belongs to the penta-EF-hand family. Its Ca(2+)-binding domain (residues 33-198) has been crystallized in the absence of Ca(2+) in two different crystal forms. Two complete data sets have been collected on a synchrotron source under cryocooling conditions from crystals grown using ammonium sulfate as precipitant: monoclinic crystals in space group C2, with unit-cell parameters a = 130.93, b = 103.85, c = 78.55 A, beta = 118.0 degrees, diffracting to 2.1 A, and tetragonal crystals in space group P42(1)2, with unit-cell parameters a = b = 103.33, c = 79.15, diffracting to 2.7 A. Crystals were also grown using PEG 6000 as precipitating agent. They also belong to space group C2, diffract to 2.8 A and their unit-cell parameters are very similar to the first form. Structure determination by molecular replacement has been initiated. Structural information should be useful for elucidating the interaction of sorcin with membrane targets.
More Related Videos
Related Concept Videos
02:52Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
00:49Ligand Binding and Linkage
01:19Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
01:25Structure of Cadherins