Crystallization and preliminary crystallographic analysis of a partial extracellular fragment of a sperm membrane protein YWK-II/APPH related to the Alzheimer betaA4-amyloid precursor protein.

Abstract

Crystals of a partial extracellular fragment of a human sperm membrane protein YWK-II/APPH have been grown at 291 K using PEG 4000 as precipitant. The diffraction pattern of the crystal extends to 2.8 A resolution at 100 K using Cu K(alpha) radiation. The crystals belong to space group P2(1)2(1)2(1), with unit-cell parameters a = 46.009, b = 67.387, c = 149.241 A, alpha = beta = gamma = 90 degrees. The presence of two molecules per asymmetric unit gives a crystal Volume per protein mass (V(M)) of 3.51 A(3) Da(-1) and a solvent content of 64.6% by Volume. A full set of X-ray diffraction data were collected to 2.8 A resolution from the native crystal.