alpha-mannosidase from rat epididymal fluid is a ligand for phosphomannosyl receptors on the sperm surface

BELMONTE, SILVIA A; CHALLA, ALEJANDRA; GUTIERREZ, LUIS S; BERTINI, FRANCISCO; SOSA, MIGUEL ANGEL

International Journal of Andrology

Blackwell Science Ltd.

Año: 1998 vol. 21 p. 277 - 282

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> alpha-Mannosidase from rat epididymal fluid is a ligand for phosphomannosyl receptors on the sperm surface.   Belmonte SA, Challa A, Gutierrez LS, Bertini F, Sosa MA.   Instituto de Histología y Embriología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina.   This study demonstrates that alpha-mannosidase from rat epididymal fluid is a ligand for phosphomannosyl receptors on the sperm surface. This enzyme was bound to intact epididymal spermatozoa with high affinity and in saturable form, and the binding was inhibited by mannose-6-phosphate but not by phosphorylated derivatives of fructose. Treatment of the enzyme with sodium periodate inhibited the binding of alpha-mannosidase, confirming that a carbohydrate residue is involved in the interaction with spermatozoa. Evidence is also presented that the cation-independent phosphomannosyl receptors are responsible for the interaction with alpha-mannosidase. These findings suggest a new role for extracellular transport mediated by the mannose-6-phosphate receptor.   PMID: 9805243 [PubMed - indexed for MEDLINE Int J Androl. 1998 Oct; 21(5):277-82.