'ZP domain' of human zona pellucida glycoprotein-1 binds to human spermatozoa and induces acrosomal exocytosis

Table 1 Binding characteristics of FITC-labelled recombinant ZP1_273-551aa with capacitated human spermatozoa in direct binding assay

Recombinant protein	Percent binding to spermatozoa (Mean ± SEM)	Statistical significance^b
Acrosome-intact sperm
Fetuin	3.95 ± 2.12
*ZP3	26.08 ± 2.75	p = 0.0004^c
*ZP1	15.63 ± 1.88	p = 0.0019^c
ZP1_273-551aa	19.67 ± 2.40	p = 0.0010^c
Acrosome-reacted sperm
Fetuin	5.8 ± 3.60
*ZP3	22.65 ± 2.15^a	p = 0.0021^c
*ZP1	14.40 ± 1.09^a	p = 0.0156^c
ZP1_273-551aa	15.62 ± 1.64^a	p = 0.0117^c

*Baculovirus-expressed recombinant human ZP1 and ZP3 labelled with FITC;
^aBinding observed only in the equatorial region
^bStatistical significance with respect to the binding values of Fetuin was calculated by one way ANOVA followed by Newman-Keuls Multiple Comparison Test.
^cValues are statistically significant.

ISSN: 1477-7827