Isolation and biological activity of the proteases released by sea urchin eggs following fertilization

Transitioning from egg to embryo: Triggers and mechanisms of egg activation

“…Upon egg activation, CGs fuse with the oocyte plasma membrane and release their contents into the perivitelline space; the CG enzymes then biochemically and structurally modify the VM so that sperm can no longer bind or remain bound to the egg. For instance, sea urchin CGs contain a serine protease that cleaves the sperm receptor, bindin, from the VM (Carroll and Epel, 1975;Glabe and Vacquier, 1978;Haley and Wessel, 1999). In mouse and sea urchin oocytes, CGs contain ovoperoxidases that harden the extracellular matrix by cross-linking tyrosine residues on adjacent proteins (Gulyas, 1979;Schmell and Gulyas, 1980;LaFleur et al, 1998).…”

Secretory functions of egg cortical granules in fertilization and development: A critical review

“…least two different proteases [Carroll, 1976;Carroll and Epel, 1975a;Carroll et al, 19771 : One protease (vitelline envelope deaminase) appears to cleave peptide bonds linking the vitelline layer to the egg's plasma membrane, while the second (sperm receptor hydrolase) Treatment of unfertilized sea urchin eggs with bovine pancreatic trypsin [Aketa et al, Eggs parthenogenetically activated by calcium ionophore A23 187 cannot be penetrated…”

Renovation of the egg extracellular matrix at fertilization

“…Although CUB domains and LDLrA repeats are common throughout the animal kingdom where they function in protein-protein binding, the fertilization envelope provides the first direct evidence that proteins with these two modules interact in a specific, high-affinity manner (Song et al, 2006). Proteolysis is one enzymatic activity considered to be conserved in the block to polyspermy (Carroll and Epel, 1975b;1975a;Runnstrom, 1966;Vacquier et al, 1973). Many functions have been ascribed to a cortical granule-derived protease, including removal of the sperm receptor, modification of the vitelline layer, and even egg activation (Carroll and Epel, 1975a;Carroll and Jaffe, 1995;Runnstrom, 1966;Vacquier et al, 1973) -yet it appears that only one enzyme is responsible for all activities.…”