title: Prostasomes from four different species are able to produce extracellular adenosine triphosphate (ATP).
abstract: BACKGROUND
  Prostasomes are extracellular vesicles. Intracellularly they are enclosed by another larger vesicle, a so called "storage vesicle" equivalent to a multivesicular body of late endosomal origin. Prostasomes in their extracellular context are thought to play a crucial role in fertilization.
  
  
  METHODS
  Prostasomes were purified according to a well worked-out schedule from seminal plasmas obtained from human, canine, equine and bovine species. The various prostasomes were subjected to SDS-PAGE separation and protein banding patterns were compared. To gain knowledge of the prostasomal protein systems pertaining to prostasomes of four different species proteins were analyzed using a proteomic approach. An in vitro assay was employed to demonstrate ATP formation by prostasomes of different species.
  
  
  RESULTS
  The SDS-PAGE banding pattern of prostasomes from the four species revealed a richly faceted picture with most protein bands within the molecular weight range of 10-150kDa. Some protein bands seemed to be concordant among species although differently expressed and the number of protein bands of dog prostasomes seemed to be distinctly fewer. Special emphasis was put on proteins involved in energy metabolic turnover. Prostasomes from all four species were able to form extracellular adenosine triphosphate (ATP). ATP formation was balanced by ATPase activity linked to the four types of prostasomes.
  
  
  CONCLUSIONS
  These potencies of a possession of functional ATP-forming enzymes by different prostasome types should be regarded against the knowledge of ATP having a profound effect on cell responses and now explicitly on the success of the sperm cell to fertilize the ovum.
  
  
  CONCLUSIONS
  This study unravels energy metabolic relationships of prostasomes from four different species.
authors.affiliation: Department of Medical Sciences, Uppsala University, Uppsala, Sweden. goran.ronquist@medsci.uu.se
authors.forename: K Göran
authors.initials: KG
authors.lastname: Ronquist
authors.forename: Bo
authors.initials: B
authors.lastname: Ek
authors.forename: Jane
authors.initials: J
authors.lastname: Morrell
authors.forename: Anneli
authors.initials: A
authors.lastname: Stavreus-Evers
authors.forename: Bodil
authors.initials: B
authors.lastname: Ström Holst
authors.forename: Patrice
authors.initials: P
authors.lastname: Humblot
authors.forename: Gunnar
authors.initials: G
authors.lastname: Ronquist
authors.forename: Anders
authors.initials: A
authors.lastname: Larsson
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis*; D000818:Animals; D002417:Cattle; D004285:Dogs; D004591:Electrophoresis, Polyacrylamide Gel; D006736:Horses; D006801:Humans; D008297:Male; D015388:Organelles / Q000378:metabolism*
chemical_list: D000255:Adenosine Triphosphate
keywords: Energy metabolism; Extracellular ATP; Microvesicles; Prostasomes; Seminal plasma