[Victor] Batista and his colleagues are proponents of a theory that smell is initiated by specific molecular interactions between odorants and G protein coupled receptors (GPCRs) in the olfactory epithelium in the nasal cavity, triggering memories and eliciting responses based on experiences with that scent. Previous research by the group identified two olfactory receptors in humans, OR5AN1 and OR1A1, that respond to musk compounds.

[...] The researchers developed structural models of OR5AN1 and OR1A1 based on quantum mechanics/molecular mechanics hybrid methods, a molecular simulation method that enables the study of chemical processes in solution and in proteins. These structural models predicted binding sites on OR5AN1 and OR1A1 for a variety of musks.

— Read more at Advancing the science of smell — with a hint of musk at Yale News. If you need a refresher course, see Shape theory of olfaction at Wikipedia.