Research

Osamu Hayaishi is distinguished for many important contributions to biochemistry, enzymology, and molecular biology, and more recently for his discoveries in the field of molecular mechanisms of sleep-wake regulation. Most importantly, he discovered oxygenases, a group of enzymes that incorporate molecular oxygen into substrates by the use of ¹⁸O in 1955. Since then, he has elucidated the structure, catalytic mechanisms and biological function of this unique group of oxido-reductase.

In the early 1980’s he discovered prostaglandin D2 to be the most abundant prostanoid in the brain of mammals and that it is the endogenous and physiological sleep promoting substances in the brain, viz., a sleep hormone. Subsequently, he elucidated the molecular mechanisms of sleep-wake regulation by prostaglandin D2, prostaglandin E2 and adenosine.