Twists of orange odorant reveal smell secrets

By contorting a molecule contributing to orange peel’s great smell into different shapes, US researchers have served up new hints about how smell works. Kevin Ryan’s team at the City College of New York explored how molecules modified from classic citrus odorant octanal fit into and activate an olfactory receptor. They occupy the receptor like keys in a lock – but then send weaker or stronger signals to our brains.