Drug giant GlaxoSmithKline (NYSE: GSK) is buying Massachusetts-based Sirtis Pharmaceuticals in a bid to broaden its drug pipeline.

The acquisition is worth $720 million.

The deal was announced Tuesday after the markets closed.

GSK maintains one of its two U.S. headquarters in RTP.

Sirtis, which went public in May of 2007, is researching enzymes known as sirutins, which are believed to be involved in the aging process and also can help a person control calorie intake. They also could be used to combat diabetes.

Sirtis shares had been selling at $12.23 before the GSK offer of $22.50 per share.

The company has 60 employs at its headquarters in Cambridge, Mass. David Sinclair, a scientist at Harvard Medical School, led much of the research that triggered the creation of the company and is a co-founder.

Sirtis recently received orphan drug status for resveratrol as a treatment of MELAS syndrome, a progressive and fatal disorder.

"Modulation of this family of enzymes is a potentially transformative science that could address diseases associated with metabolism and ageing such as diabetes, muscle wasting, and neurodegeneration," said Moncef Slaoui, head of research and development for GSK. "This acquisition continues GSK’s strategy of pursuing the best new science, externally or internally, to bring new medicines to patients and value to the GSK pipeline. Our intent is to retain all Sirtris employees and continue the entrepreneurial and innovative culture they created."