Minelli A, Allegrucci C, Liguori L, Ronquist G. Ecto-diadenosine polyphosphates hydrolase activity on human prostasomes.
Prostate 2002;
51:1-9. [PMID:
11920952 DOI:
10.1002/pros.10062]
[Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND
Ecto-diadenosine polyphosphates are ubiquitous compounds with several physiological roles. Ecto-diadenosine polyphosphates hydrolase control their actions by degrading and terminating their signaling. The present work deals with the identification and partial characterization of ecto-diadenosine polyphosphates hydrolase on human prostasomes.
METHODS
Reverse-phase and paired-ion HPLC techniques have been used.
RESULTS
Prostasomes have an ecto-diadenosine polyphosphates hydrolase that leads to the degradation of several diadenosine compounds. Kinetic parameters of the enzyme show that diadenosine tetraphosphate is the preferred substrate that is further metabolized by the prostasome-ecto-nucleotidases to adenosine. The ecto-enzyme is bound to the prostasome-membranes through a GPI-anchor and is activated by physiological concentration of Ca+2, Mg+2, and Mn+2. Its optimum pH is also in the slightly alkaline physiological range. Human spermatozoa do not possess this hydrolytic activity, but they can acquire it after fusion with prostasomes.
CONCLUSIONS
The existence of an enzyme capable of degrading diadenosine compounds and can be transferred to human spermatozoa suggests new physiological implications for the role of prostasomes in fertilization.
Collapse