Felinine

Abstract: Bobcat (Lynx rufus) urine reduces scent-marking activity of woodchucks (Marmota monax) and feeding activity of snowshoe hares (Lepus americanus) and deer (Odocoileus virginianus, O. hemionus). In order to identify the semiochemicals responsible for these behavior modifications, a dichloromethane extract of the bobcat urine was analyzed by GC-MS. Among the known compounds identified in the extract are phenol, indole, dimethyl sulfone, and 3-mercapto-3-methylbutanol. Compounds for which spectroscopic data are presented for the first time include one sulfide, two disulfides, and two trisulfides. The sulfur compounds are derived from an amino acid,S-(l,1-dimethyl-3-hydroxypropyl)cysteine (“felinine”), which was identified several years ago in the urine of the domestic cat (Felis domesticus).

Abstract: Cauxin is an abundant protein in feline urine. We have used proteomics strategies to characterize cauxin from the urine of domestic cats and a number of big cat species. Proteins were resolved by gel-based electrophoretic purification and subjected to in-gel digestion with trypsin. The resultant tryptic peptides were mass-measured by matrix-assisted laser desorption ionization time of flight mass spectrometry. Peptides were also resolved by liquid chromatography and analyzed by electrospray ionization and tandem mass spectrometry to generate fragment ion data to infer the amino acid sequence. We identified cauxin polymorphisms and corrected a sequencing artifact in cauxin from the domestic cat. The proteomics data also provided positive evidence for the presence of a cauxin homolog in the urine of big cats (Pantherinae), including the Sumatran tiger, Asiatic lion, clouded leopard, Persian leopard, and jaguar. The levels of cauxin in the urine of all big cats were substantially lower than that in the urine of intact male domestic cats.