title: Purification and preliminary X-ray crystallographic studies of beta-microseminoprotein from human seminal plasma.
abstract: beta-Microseminoprotein (beta-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 beta-MSP proteins suggests that the protein is a rapidly evolving protein. The function of beta-MSP is poorly understood. Furthermore, no crystal structure has been reported of any beta-MSP; therefore, determination of the crystal structure of beta-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 beta-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 P4(3)22 and contained three beta-MSP molecules in the asymmetric unit. X-ray intensity data were collected to 2.4 A resolution.
authors.affiliation: Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Vijay
authors.initials: V
authors.lastname: Kumar
authors.forename: Yvette
authors.initials: Y
authors.lastname: Roske
authors.forename: Nagendra
authors.initials: N
authors.lastname: Singh
authors.forename: Udo
authors.initials: U
authors.lastname: Heinemann
authors.forename: Tej P
authors.initials: TP
authors.lastname: Singh
authors.forename: Savita
authors.initials: S
authors.lastname: Yadav
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D006801:Humans; D029584:Prostatic Secretory Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D012661:Semen / Q000737:chemistry*
chemical_list: D029584:Prostatic Secretory Proteins; C043076:beta-microseminoprotein