Modifying preselected sites on proteins: the stretch of residues 633-642 of the myosin heavy chain is part of the actin-binding site.

We have designed an "antipeptide" capable of firmly and specifically interacting with a preselected stretch of myosin S-1 heavy chain. Covalent attachment of this antipeptide to its target stretch, residues 633-642, does not affect the intrinsic ATPase activities of the protein but significantly reduces the actin-binding capabilities of the myosin head.