Brian Kobilka, co-winner of the 2012 Nobel Prize in Chemistry, said on Wednesday that "irrational optimism" has been keeping him motivated during his scientific pursuits.

"Even though something fails...you'll think of an idea and it's, 'Oh this one is going to work!' So you just keep thinking that something's going to work," said Kobilka at a press conference in Stanford University.

Earlier Wednesday, Kobilka was awarded the honor along with his former mentor Robert Lefkowitz in Duke University for their work on G-protein-coupled receptors (GPCRs), a large protein family that convey chemical messages into the cell's interior from outside through the cell membrane.

In the 1980s, Kobilka isolated the gene for one member of the GPCRs family called the beta-adrenergic receptor after he and his mentor identified the receptor.

Around 800 different GPCRs have been identified so far. They are one of the largest families of human proteins, on which nearly every function of the human body depends, from sight, smell to heart rate and neuronal communication.

Today, GPCRs represent one of the most valuable families of drug target. Around 30 to 40 percent of all drugs sold worldwide are GPCR-targeting drugs.

In 2011, Kobilka and his team obtained a three-dimensional image of a receptor when it is activated by a hormone and sends a signal into the cell, providing a better understanding to the structure of the receptor.

Kobilka described the breakthrough as the most significant " eureka" moment in his career, noting that he hopes the discovery may lead to better and less-expensive drugs for diseases like diabetes, obesity or even cancer.

Kobilka and his team now are trying to develop structure-based approaches to look for new drugs.

Regardless of his new fame, the professor struggled to get funding during his early years. "I don't think I ever considered giving up. I admit that it was frustrating at times, but I enjoyed the challenge and I wanted to know the answer," Kobilka told Nature magazine last year.

"His work is a testament to the importance of supporting basic science research -- whose payoff can take many years or decades to reach fruition but, when it does, it changes the direction of medicine and science," Philip Pizzo, dean of Stanford School of Medicine, said on Wednesday.

Kobilka, 57, was son of a bakery owner in a tiny Minnesota town in the Midwestern U.S. His family and colleagues described him as a shy and humble man who likes working alone in his lab and teaching young scientists. He told reporters that he likes cycling in his spare time.

VietNamNet/Xinhuanet