1. Potato aspartic proteases (StAPs) exert cytotoxic activity on bovine and human spermatozoa 
Andreina Cesari, Ph.D., Andrea L. Falcinelli, B.S., Julieta R. Mendieta, B.S., Mariana R. Pagano, Ph.D., Nicolas Mucci, Ms. Vet., Gustavo R. Daleo, Ph.D., María G. Guevara, Ph.D. 
Fertility and Sterility 
Volume 88, Issue 4, Pages (October 2007)
DOI: /j.fertnstert
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

2. Figure 1
Sperm immobilizing ability of StAPs. Comparison of effect of StAP1 (A), StAP3 (B) and control proteins (C) over cryopreserved bovine spermatozoa. The immobilization effect is represented as total (light blue) and progressive (red) motility related to nontreated sperm (mean + SEM of four semen samples) as a function of StAPs concentration (μM). Different letters mean values significantly different (P<.01; analysis of variance [Proc GLM, SAS] + Tukey's test).
Cesari. Spermicidal activity of StAPs. Fertil Steril 2007.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

3. Figure 2
Bovine sperm nonspecific aggregation. The StAPs at EC50 (B) were tested against bovine sperm suspensions (5 × 106 spermatozoa/mL) after incubation at 37°C for 5 minutes. As a control (A), sperm suspensions were kept in phosphate-buffered saline in the same conditions. Head-to-head agglutination was examined microscopically under ×400 magnification. Bars: 9.2 μm.
Cesari. Spermicidal activity of StAPs. Fertil Steril 2007.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

4. Figure 3
StAPs interaction with bovine sperm surface. Bovine cryopreserved-thawed nonpermeabilized spermatozoa were incubated with FITC-labeled StAP1 (A, B), FITC- labeled StAP3 (C, D) at a concentration corresponding to their EC50 previously obtained or 2.5 μM FITC-labeled Pepsin (E, F) for 5 minutes at 37°C. All the samples assayed (four replicates) had an initial motility by approximately 80%. Spermatozoa were wet-mounted on slides and examined under ×400 magnification. Panels A, C, and E are phase contrast images. Bars: 9.2 μm.
Cesari. Spermicidal activity of StAPs. Fertil Steril 2007.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

5. Figure 4
Cytotoxic activity of StAPs on bovine sperm. Sperm membrane integrity was assessed by SYTOX Green uptake after 5 minutes of incubation with different concentrations of StAP1 (yellow) or StAP3 (red) at 37°C (mean + SEM of four semen samples). SYTOX Green uptake is represented by the increase in the binding of the dye to DNA (495 nm excitation, 538 nm emission) measured in a fluoroscan II microtiter plate reader. Different letters mean values significantly different (P<.01; analysis of variance [Proc GLM, SAS] + Tukey's test).
Cesari. Spermicidal activity of StAPs. Fertil Steril 2007.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

6. Figure 5
Cytotoxic activity of StAPs on human sperm. Sperm membrane integrity was assessed by SYTOX Green uptake after 5 minutes of incubation with different concentrations of StAP1 (yellow) or StAP3 (red) at 37°C (mean + SEM of four semen samples). Different letters mean values significantly different (P<.01; analysis of variance [Proc GLM, SAS] + Tukey's test).
Cesari. Spermicidal activity of StAPs. Fertil Steril 2007.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions