IIB   20738
INSTITUTO DE INVESTIGACIONES BIOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
StAsp-PSI DOMAIN IS THE KEY IN THE StAPs SPERMICIDAL ACTIVITY
Autor/es:
ROBUSCHI L, MUÑOZ F, DALEO GR, CESARI A, GUEVARA MG
Lugar:
Villa Carlos Paz, Córdoba, Argentina
Reunión:
Congreso; XLIV Reunión anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2008
Resumen:
<!-- /* 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;} --> We have isolated two potato aspartic porteases (StAPs) with cytotoxic effect towards plant and human pathogens and on bovine and human sperm. StAPs exert its cytotoxic activity by selective plasma membrane permeabilization. Cytotoxic activity of  StAPs is related with the presence in these proteins of a domain named Plant Specific Insert (PSI), which has high structural homology with proteins able to interact with different phospholipids (SAPLIPs). The aim of this work was to analyse the capacity of this domain, StAsp-PSI, to interact with the plasma membrane and to exert spermicidal activity over bovine and human sperm, both cryopreserved and fresh. StAsp-PSI reduced, in a dose-dependent manner (0.6-12.5 uM), bovine and human sperm total motility (100% at concentrations of 12.5 and 2.4uM respectively) and increased sperm membrane permeability (100% at concentrations of 12.5 and 7.5uM respectively). These results suggest that StAsp-PSI is the key domain into the StAPs to exert spermicidal activity. However, contrary with the results reported for StAPs, StAsp-PSI was unable to bind to spermatozoa surface, independently of the specie and conservation method. Therefore, correct folding in the structure of mature protein or another StAPs domain is necessary for binding to spermatozoa surface.