title: Ion-exchange chromatography used to isolate a spermadhesin-related protein from domestic goat (Capra hircus) seminal plasma.
abstract: Mammalian seminal plasma contains among others, proteins called spermadhesins, which are the major proteins of boar and stallion seminal plasma. These proteins appear to be involved in capacitation and sperm-egg interaction. Previously, we reported the presence of a protein related to spermadhesins in goat seminal plasma. In the present study, we have further characterized this protein, and we propose ion-exchange chromatography to isolate this seminal protein. Semen was obtained from four adult Saanen bucks. Seminal plasma was pooled, dialyzed against distilled water and freeze-dried. Lyophilized proteins were loaded onto an ion-exchange chromatography column. Dialyzed-lyophilized proteins from the main peak of DEAE-Sephacel were applied to a C2/C18 column coupled to an RP-HPLC system, and the eluted proteins were lyophilized for electrophoresis. The N-terminal was sequenced and amino acid sequence similarity was determined using CLUSTAL W. Additionally, proteins from DEAE-Sephacel chromatography step were dialyzed and submitted to a heparin-Sepharose high-performance liquid chromatography. Goat seminal plasma after ion-exchange chromatography yielded 6.47 +/- 0.63 mg (mean +/- SEM) of the major retained fraction. The protein was designated BSFP (buck seminal fluid protein). BSFP exhibited N-terminal sequence homology to boar, stallion and bull spermadhesins. BSFP showed no heparin-binding capabilities. These results together with our previous data indicate that goat seminal plasma contains a protein that is structurally related to proteins of the spermadhesin family. Finally, this protein can be efficiently isolated by ion-exchange and reverse-phase chromatography.
authors.affiliation: Laboratório de Fisiologia e Controle da Reprodução, Universidade Estadual do Ceará, Fortaleza, CE, Brazil.
authors.forename: Dárcio Italo Alves
authors.initials: DI
authors.lastname: Teixeira
authors.forename: Luciana Magalhães
authors.initials: LM
authors.lastname: Melo
authors.forename: Carlos Alberto de Almeida
authors.initials: CA
authors.lastname: Gadelha
authors.forename: Rodrigo Maranguape Silva da
authors.initials: RM
authors.lastname: Cunha
authors.forename: Carlos
authors.initials: C
authors.lastname: Bloch
authors.forename: Gandhi
authors.initials: G
authors.lastname: Rádis-Baptista
authors.forename: Benildo Sousa
authors.initials: BS
authors.lastname: Cavada
authors.forename: Vicente José de Figueirêdo
authors.initials: VJ
authors.lastname: Freitas
mesh_terms: D000818:Animals; D002852:Chromatography, Ion Exchange / Q000379:methods*; D006041:Goats; D008297:Male; D012661:Semen / Q000737:chemistry*; D029589:Seminal Plasma Proteins / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D029589:Seminal Plasma Proteins; C425042:spermadhesin