title: Crystallization and preliminary crystallographic analysis of extracellular fragment X3 of YWK-II/APPH: a human sperm membrane protein related to the Alzheimer betaA4-amyloid precursor protein.
abstract: Crystals of extracellular fragment X3 of a human sperm membrane protein YWK-II/APPH have been grown at 291 K using 8% PEG 4000 as precipitant by the vapour-diffusion method. The diffraction pattern of the crystal extends to 2.9 A resolution at 100 K using Cu Kalpha radiation in-house. The crystals belong to space group P2(1), with unit-cell parameters a = 46.0, b = 43.7, c = 90.2 A, alpha = gamma = 90.0, beta = 106.6 degrees. Furthermore, a selenomethionine (SeMet) derivative of the protein was overexpressed in the same expression system and was purified in a reducing environment. The derivative crystals were obtained under similar conditions. Subsequently, a single-wavelength data set was collected to 2.38 A resolution from the derivative crystal at ESRF. The crystals belong to space group P2(1), with unit-cell parameters a = 46.2, b = 44.0, c = 88.3 A, alpha = gamma = 90.0, beta = 103.6 degrees. The presence of one molecule per asymmetric unit gives a crystal Volume per protein mass (V(M)) of 2.8 A(3) Da(-1) and a solvent content of 56.4% by Volume.
authors.affiliation: National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005, People's Republic of China.
authors.forename: Maojun
authors.initials: M
authors.lastname: Yang
authors.forename: Weihong
authors.initials: W
authors.lastname: Zhou
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.forename: Wangjun
authors.initials: W
authors.lastname: Hu
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.forename: Hai
authors.initials: H
authors.lastname: Pang
authors.forename: Shiying
authors.initials: S
authors.lastname: Miao
authors.forename: Linfang
authors.initials: L
authors.lastname: Wang
authors.forename: Zihe
authors.initials: Z
authors.lastname: Rao
mesh_terms: D016564:Amyloid beta-Protein Precursor / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D008566:Membranes / Q000737:chemistry; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments / Q000737:chemistry; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry; D012645:Selenomethionine / Q000737:chemistry; D013094:Spermatozoa / Q000737:chemistry*
chemical_list: C489697:APLP1 protein, human; C084104:APLP2 protein, human; D016564:Amyloid beta-Protein Precursor; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D012645:Selenomethionine