H. Tsubamoto et al., BINDING OF RECOMBINANT PIG ZONA-PELLUCIDA PROTEIN-1 (ZP1) TO ACROSOME-REACTED SPERMATOZOA, Journal of Reproduction and Fertility, 1996, pp. 63-67
In an immunofluorescent study, recombinant pig zona pellucida protein
1 (pZP1) produced in Escherichia coli bound to acrosome-reacted sperma
tozoa from five different mammals. The location of the binding site mo
ved from the equatorial region to the midpiece and tail regions during
the incubation. This finding suggests that pig ZP1 acts as a secondar
y sperm-binding receptor in an interspecies manner and assists penetra
tion of the spermatozoa through the zona pellucida. The recombinant pZ
P1 bound to 55 kDa protein (proacrosin) and 40 kDa protein of the boar
spermatozoa as revealed by immunoblotting.