Acta Crystallographica Section F

Structural Biology and Crystallization Communications

Volume 64, Part 2 (February 2008)

crystallization communications

Acta Cryst. (2008). F64, 133-136 [ doi:10.1107/S1744309108001905 ]

Crystallization and preliminary crystallographic analysis of human Ca²⁺-loaded calbindin-D28k

C. Zhang, Y. Sun, W. Wang, Y. Zhang, M. Ma and Z. Lou

Abstract: Calbindin-D28k is a calcium-binding protein that belongs to the troponin C superfamily. It is expressed in many tissues, including brain, intestine, kidney and pancreas, and performs roles as both a calcium buffer and a calcium sensor and carries out diverse physiological functions of importance. In order to resolve the crystal structure of human calbindin-D28k and to gain a better understanding of its biological functions, recombinant human calbindin-D28k was crystallized at 291 K using PEG 3350 as precipitant and a 2.4 Å resolution X-ray data set was collected from a single flash-cooled crystal (100 K). The crystal belonged to space group C2, with unit-cell parameters a = 108.1, b = 28.2, c = 70.6 Å, [beta] = 107.8°. The presence of one molecule per asymmetric unit is presumed, corresponding to a Matthews coefficient of 1.75 Å³ Da^-1.

Keywords: calbindin-D28k; calcium-binding proteins.