以表彰他多年來對於 GPCR (G-蛋白質偶合接受體) 的關鍵性的貢獻。此貢獻對於尋找有效的藥品提供了極重要的新思路。
生物體內有某種細胞藉著釋放化學物質，傳遞到其他細胞，以控制他們的行為。這些化學物質可控制生命中重要的過程，諸如腦功能、心臟泵血及生殖等等現象。羅伯特・尼科威教授(Professor Robert Lefkowitz)從事這方面研究達三十五年，揭示了這些化學信號如何被細胞接受和表達的奧秘。其關鍵在於受體細胞膜表面具有一組G-蛋白偶聯受體(GPCR)。GPCR與其他受體不同，來回穿膜七次，又稱七次穿膜受體。在1970年代，尼科威教授開始設法分離這種受體及鑒定其結構，當時七次穿膜受體仍是個理論的概念。在1986年尼科威教授和Merck Sharp 和 Dohme研究所的同事合作，分離了第一個這類受體的基因並闡明它的初級蛋白結構，是一項重要突破。從此尼科威教授和其他科學家，努力不懈，陸續發現上百種這類受體，不同受體各有分工，針對特有的化學信號。尼科威教授更進一步發現，這類受體並不是一直激活的，他們傳遞信息後，就被另一種反饋機制沈默，以防止過度的刺激。在研究反饋機制的過程中，尼科威教授又發現一類新蛋白。他們不但能沈默受體，且在生理上有重要的功能，例如控制細胞的生長和分化。許多科學家從事有關信號傳遞的研究，各有貢獻，但尼科威教授卻首創先河，一直領先。許多沿用已久的藥物，能有效治病，但人們知其然而不知其所以然；經過尼科威教授的研究，製藥公司現在才進一步瞭解，這些藥物如何控制疾病。這些藥物包括用於高血壓和心臟衰竭的β-阻斷劑（如propronolol）；醫治胃潰瘍的H2拮抗劑（如cimetidine）；醫治過敏症的H1拮抗劑（如chlorpheniramine）和治療精神分裂症的多巴胺拮抗劑（如clozapine）。利用這方面的知識，藥廠可以尋找更多新藥物，針對這類G-蛋白偶聯受體，來治療各種疾病。
The human body is made up of many different types of tissues and many different kinds of cells. To co-ordinate body functions, cells signal to other cells in the same organ and in different organs by releasing chemical messengers that travel through the bloodstream. The chemical messengers control all of the vital body processes. For example, they determine the force of a heartbeat and the number of beats per minute, the height of the blood pressure, and the propulsive energy of the intestine. In the brain these chemicals profoundly influence our moods and our behavior, including our drives for food and sex. When Lefkowitz began his work in the late 1960’s, scientists had already identified several chemical messengers but they did not know how these chemicals affected the target cells so as to alter their behavior. Over the subsequent 35 years Lefkowitz and his students painstakingly elucidated a family of molecules on the surface of target cells that receive the chemical messages. These receiving molecules are known as G protein-coupled receptors (GPCRs).
GPCRs are proteins embedded in the surface membrane of target cells with their receiving ends facing the outside fluid. Each cell produces many different GPCRs, each tuned to respond to different chemical messengers. For example, certain GPCRs called beta-adrenergic receptors located on heart muscle cells recognize adrenalin secreted by the adrenal gland and thereby control the heartbeat. When a human is physically threatened, the adrenal gland releases adrenalin which travels through the bloodstream and attaches to beta-adrenergic receptors on heart muscle. Once stimulated by the adrenalin, the receptors initiate a cascade of events that causes the heart to beat stronger and faster. This prepares the threatened person for “fight or flight”.
