Open AccessPurification and preliminary X‐ray crystallographic studies of β‐microseminoprotein from human seminal plasma
Author(s) -
Kumar Vijay,
Roske Yvette,
Singh Nagendra,
Heinemann Udo,
Singh Tej P.,
Yadav Savita
Publication year - 2009
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309109013670
Subject(s) - crystallization , protein crystallization , molecular mass , chemistry , tetragonal crystal system , crystallography , x ray crystallography , size exclusion chromatography , crystal (programming language) , crystal structure , cysteine , beta (programming language) , peptide sequence , biochemistry , diffraction , enzyme , gene , physics , programming language , organic chemistry , optics , computer science
β‐Microseminoprotein (β‐MSP) is a small cysteine‐rich protein with a molecular mass of 10 kDa. It was first isolated from human seminal plasma and has subsequently been identified from several species. Comparison of the amino‐acid sequences of β‐MSP proteins suggests that the protein is a rapidly evolving protein. The function of β‐MSP is poorly understood. Furthermore, no crystal structure has been reported of any β‐MSP; therefore, determination of the crystal structure of β‐MSP is the foremost task in order to understand the function of this protein completely. Here, the purification, crystallization and preliminary X‐ray diffraction analysis of β‐MSP from human seminal plasma are described. The protein was purified using anion‐exchange and size‐exclusion chromatography and the purified protein was crystallized using 0.1 M ammonium sulfate, 0.1 M HEPES buffer pH 7.0 and 20%( w / v ) PEG 3350. The crystals belonged to the tetragonal space group P 4 3 22 and contained three β‐MSP molecules in the asymmetric unit. X‐ray intensity data were collected to 2.4 Å resolution.