Effects of amino acid substitutions in and around the arginine-glycine-aspartic acid (RGD) sequence on fertilization and parthenogenetic development in mature bovine oocytes

Integrins have been shown to be involved in the process of fertilization and many integrin-ligand interactions are mediated through the recognition of an arginine-glycine-aspartic acid (RGD) sequence. A set of linear peptides in which the amino acid sequence in and around the RGD tri-peptide was modified and synthesized to better understand the specificity of the RGD-receptor interaction. Mature oocytes were fertilized in vitro in the presence of RGD-containing and RGD-modified peptides at two different concentrations. Both the RGD-containing and RGD-modified peptides impaired the ability of sperm to fertilize the bovine oocyte, illustrated by a reduction in cleavage. The linear modified RGD containing peptides were also examined for their ability to induce parthenogenetic development at three different concentrations. The parthenogenetic development data did not result in a single peptide with greater biological activity than G RGDSPK, nor one that would eliminate the requirement for a second factor to produce "complete activation".