Anion-mediated lysine—arginine interaction evidence in Chaetopterus variopedatus sperm protamine

Abstract

Chaetopterus ariopedatus sperm protamine is a stable oligomer. Specific amino acid side chain modifications show that the oligomeric structure depends on anion-mediated lysine—arginine interactions. The occurrence of this type of interaction is confirmed by the finding that Poly- l-arginine readily forms aggregates with Poly- l-lysine or with the native but not with the protamine with carbamylated ε-amino groups.