title: Increased expression of secretory actin-binding protein on human spermatozoa is associated with poor semen quality.
abstract: BACKGROUND
  Antibodies to human sperm are useful diagnostic reagents for detection of changes in sperm protein expression and their relationship with sperm defects and male infertility. The specificity of Hs-16 monoclonal antibody (mAb) and the localization and frequency of the occurrence of Hs-16-recognized protein on human spermatozoa were investigated.
  
  
  METHODS
  Samples from 30 fertile men with normal spermiograms and 30 men with pathological spermiograms were studied. The specificity of Hs-16 mAb was analysed by the western blotting technique and matrix-assisted laser desorption/ionization mass spectrometry. Indirect immunofluorescence with Hs-16 antibody was used to test sperm ejaculates.
  
  
  RESULTS
  The Hs-16 antibody detected a human sperm and seminal plasma protein, which was determined to be secretory actin-binding protein (SABP). This specificity was also verified by co-localization of SABP and actin on spermatozoa with Hs-16 and anti-actin antibodies, and partial co-localization of these proteins was found. SABP was localized on the sperm tail, mainly in the midpiece of the tail. Other parts of spermatozoa were labelled with lower frequency. A significant difference was found in SABP labelling between men with normal spermiograms and donors with asthenozoospermia or oligoasthenoteratozoospermia (both P < 0.01), and asthenozoospermia versus oligoasthenoteratozoospermia (P < 0.05). Increased expression of SABP was observed in men with pathological spermiograms.
  
  
  CONCLUSIONS
  Hs-16 antibody reacts specifically with SABP. SABP can serve as a marker of defective sperm and may be associated with fertility failure.
authors.affiliation: Department of Biology and Biochemistry of Fertilization, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic. capkova@biomed.cas.cz
authors.forename: Jana
authors.initials: J
authors.lastname: Capková
authors.forename: Fatima
authors.initials: F
authors.lastname: Elzeinová
authors.forename: Petr
authors.initials: P
authors.lastname: Novák
mesh_terms: D000199:Actins / Q000032:analysis; D000328:Adult; D000911:Antibodies, Monoclonal; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D008297:Male; D008840:Microfilament Proteins / Q000096:biosynthesis* / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013094:Spermatozoa / Q000276:immunology / Q000378:metabolism*
chemical_list: D000199:Actins; D000911:Antibodies, Monoclonal; D008840:Microfilament Proteins