Sulbactam is a β-lactamase inhibitor useful in combination with β-lactam antibiotics to increase their potency. It irreversibly inactivates β-lactamase enzymes, preventing them from degrading β-lactam antibiotics. Sulbactam has been used in combination with ampicillin and cefoperazone to inhibit β-lactamase enzymes during Agrobacterium-mediated plant genetic modifications. It may also be used in cell signaling studies.