title: Purification and partial characterization of proteinase inhibitors of equine seminal plasma.
abstract: The aims of the study were: 1/ to isolate and identify equine seminal plasma proteinase inhibitors, 2/ to evaluate their inhibitory potential, and 3/ to test a correlation between protein concentration in seminal plasma supernatant (obtained after precipitation with 36% ammonium sulfate) and stallion sexual maturity. Seminal plasma proteins obtained from six stallions were chromatographed in a Superose 12 (FPLC system) column followed by C(18) HPLC reverse-phase. Inhibition of trypsin amidase activity was evaluated in the collected fractions. Active proteins with a molecular mass of 6.3-7.0 KDa were identified using mass spectrometry. The older stallions showed a reduction in total seminal plasma protein concentration, but had similar concentrations of proteinase inhibitors (0.28+/-0.10 mg/ml) in seminal plasma supernatant. Different proteinase inhibitor isoforms were found in semen of all stallions which suggests that the isoforms may be used as biomarkers of individual animals.
authors.affiliation: Institute of Veterinary José Caetano Borges,, University of Uberaba, Uberaba, Minas Gerais, Av. Tutunas 720, Postal code 38061-500, Brazil. andre_belico@yahoo.com.br
authors.forename: André Belico
authors.initials: AB
authors.lastname: Vasconcelos
authors.forename: Alexandre Martins Costa
authors.initials: AM
authors.lastname: Santos
authors.forename: Jamil Silvano
authors.initials: JS
authors.lastname: Oliveira
authors.forename: Monique de Albuquerque
authors.initials: Mde A
authors.lastname: Lagares
authors.forename: Marcelo Matos
authors.initials: MM
authors.lastname: Santoro
mesh_terms: D000375:Aging; D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D006736:Horses / Q000378:metabolism*; D008297:Male; D013058:Mass Spectrometry; D011480:Protease Inhibitors / Q000737:chemistry / Q000302:isolation & purification*; D012661:Semen / Q000737:chemistry*; D029589:Seminal Plasma Proteins / Q000032:analysis / Q000302:isolation & purification; D015842:Serine Proteinase Inhibitors / Q000302:isolation & purification
chemical_list: D011480:Protease Inhibitors; D029589:Seminal Plasma Proteins; D015842:Serine Proteinase Inhibitors