entering the acidic environment of the stomach. Antimicrobial enzymes that kill bacteria. Lysozyme Salivary lactoperoxidase Lactoferrin [10] Immunoglobulin A [10] Proline -rich proteins (function in enamel formation, Ca2+-binding, microbe killing and lubrication) [10] Minor enzymes include salivary acid phosphatases A+B, N-acetylmuramoyl-L-alanine amidase , NAD(P)H dehydrogenase (quinone) , superoxide dismutase , glutathione