2-sec-Butyl-4,5-dihydrothiazole

A volatile pheromone found in rodents such as mice and rats, SBT is excreted in the urine and promotes aggression amongst males while inducing synchronized estrus in females.

[2] Mouse major urinary proteins (MUPs) are responsible for binding to hydrophobic ligands such as the pheromone SBT.

SBT binds within MUP-I's barrel-shaped active site, forming a hydrogen bond with a water molecule within the active site, which in turn is stabilized by forming hydrogen bonds with residue Phe56 and another water molecule; this second water molecule also forms hydrogen bonds to residues in the active site, namely Leu58 and Thr39.

SBT also forms van der Waals forces with several of MUP-I's residues, including Ala121, Leu123, Leu134, Leu72, Val100, and Phe108.

When bound, MUP safely carries SBT through the aqueous environment; once the protein-ligand complex is excreted in the urine, MUP helps prevent SBT decomposition and controls the slow release of SBT over a prolonged period of time, resulting in the physiological and behavioral responses of animals who come into contact with the pheromone.