Histatin 3 is one of the parent histatins secreted by human salivary glands, a family of histidine-rich cationic peptides that form part of the innate antifungal defence of the oral cavity. At a molecular weight above 4000 it is the longest of the histatins offered here, and it is the precursor from which several shorter family members arise. That precursor relationship is the reason to work with histatin 3 specifically. Proteolytic processing in saliva converts it into shorter peptides, the best known being histatin 5, which corresponds to the N-terminal portion and carries most of the candidacidal activity. Studying the parent rather than the fragment is therefore appropriate when the question concerns how salivary proteolysis generates the active repertoire, how stable the intact peptide is in whole saliva, or whether the full-length molecule has activities the fragments lack. Histatin 3 has separately been of interest for wound-healing-related activity in oral tissue, an area where the longer histatins are studied alongside their antifungal role. For antifungal assays where the object is maximal killing of Candida albicans rather than the processing pathway, histatin 5 (LT1595) is the more direct reagent and the one most of the mechanistic literature uses. Histatin 3 is the choice when the precursor itself, or the conversion between forms, is the subject of the experiment. | 