Fatty amines and 1-monoglycerides with cytotoxic activity serve as ligands for a multipurpose receptor CD36

Cluster of differentiation 36 (CD36) is a cell-surface receptor that exhibits multifunctional properties with diverse ligands. A short segment of CD36, consisting of amino acids 149-168 (CD36149-168), has been shown to constitute a site for recognizing its lipid ligands (e.g., distinct forms of oxidized phospholipids). Recently, lauric acid was found to bind to the CD36 segment. Of interest, the fatty acid and some of its derivatives such as laurylamine and 1-monolaurin are well known to have a cytotoxic activity. This study aimed to assess whether lipids with cytotoxicity, including lauric acid derivatives, could be CD36 ligands by conducting an assay in which a fluorescently-labeled peptide containing human CD36149-168 was utilized. The assay results indicated that laurylamine and 1-monolaurin could bind to CD36149-168. Conversely, no evidence was obtained for non-cytotoxic derivatives (e.g., lauryl mercaptan) interacting with the CD36 segment. Other cytotoxic fatty amines (e.g., myristylamine) and 1-monoglycerides (e.g., 1-monocaprin) were also shown to be recognized by CD36149-168. Identification of these lipids offers an additional category for CD36 ligands, namely, "cytotoxic lipids," which further supports the role of this receptor as a multipurpose player.