PROVIDENCE — U.S. Rep. David R. Obey, chairman of the House Appropriations Committee, toured four major research institutions in the city’s Jewelry District on Friday along with Rep. Patrick J. Kennedy, Mayor David N. Cicilline, Governor Carcieri and other state leaders.

The group of about 30 city and state officials and local entrepreneurs visited Lifespan’s Coro Center, Brown University’s Laboratories for Molecular Medicine, the biomedical firm EpiVax and the Kilguss Research Institute of Women & Infants Hospital.

The purpose of the tour was to show Obey, a Wisconsin Democrat, what federal investment has done to help grow Rhode Island’s research and science institutions and to stress the need for increased federal funding in the life sciences for the state’s economic future, according to Kennedy, who is also a member of the appropriations committee, which oversees the federal budget.

Rhode Island, which suffers from one of the highest unemployment rates in the nation, at 13 percent, has made the city’s Jewelry District a pillar of its economic-development plan.

State leaders hope that turning the former center of costume-jewelry manufacturing into a hub of biotech, life science and “knowledge-based” industries — similar to Boston’s Route 128 corridor or North Carolina’s Research Triangle — will help resolve many of the state’s chronic shortcomings, from its difficulty in attracting major companies and creating new industries, to retaining college students after graduation and providing job opportunities for low-skilled residents.

City hospitals, universities and other major nonprofit institutions have already committed major investments in the neighborhood.

Brown University, for example, envisions a new downtown campus centered along Richmond Street in the Jewelry District to be anchored by its Warren Alpert Medical School, which is expected to open in 2011.

Acres of land will open up in the next two years as the old Route 195 is demolished, presenting an opportunity for additional expansion of research labs, office and residential space.

Kennedy and others contended on Friday that an essential part of the vision is increased federal funding to build on existing research development and investment in the district.

“The merits are here,” Kennedy said. “But the political case needs to be made … We have got to make the case to the White House that we deserve federal support.”

Cicilline said federal investment is crucial to the city’s efforts to accelerate development and become a leader in the “global knowledge economy.”

Obey, following the two-hour tour, seemed supportive of the state’s vision. The district is a “solid engine for growth,” he said. “This is a good investment for Rhode Island. We need to be doing dozens of these in the U.S. as a whole.”

The tour started at the Coro Center, off Point Street, where the group learned how federal funding is helping scientists advance stem cell research.

Just a few blocks away, at Brown University’s Laboratories for Molecular Medicine, on Ship Street, they observed a demonstration of the university’s x-ray crystallographer, which helps scientists determine the arrangement of atoms within a crystal and learned about a $26-million federal grant for the university’s Superfund Research Program, which studies contaminated industrial sites in Rhode Island.

At an office building on Clifford Street, Dr. Annie S. DeGroot explained how her 11-year-old firm, EpiVax, is carving a niche in infectious and autoimmune disease research, including the development of a possible AIDS vaccine.

The tour ended at the Kilguss Research Institute of Women & Infants Hospital, where researchers, funded by the National Institutes of Health, are studying heart and lung development in fetuses and babies. (Obey and Kennedy also visited Thundermist Health Center in Woonsocket later in the day.)

At each place, researchers emphasized the value of being located within a growing cluster of research institutions and laboratories, and being within walking distance of most of the city’s six hospitals.

“It’s a really collaborative environment in the Jewelry District,” said Dr. James F. Padbury, pediatrician-in-chief at Women & Infants. “We share use of high-end machines. We write grants together … It’s a really fun environment.”

DeGroot, chief executive officer of EpiVax, said she came to the district three years ago from a location elsewhere in the city. “I said, ‘This is it. This is where I want to be,’ ” she said. “We’re definitely here to stay.”

Researchers also spoke about the work they hope to accomplish with federal funds they’ve recently applied for.

Padbury, of Kilguss, said that Brown and the University of Rhode Island have applied for a $20-million grant from the National Institutes of Health to build a new Center for Clinical and Translational Sciences, which would research ways to improve patient care.

And Dr. Wolfgang Peti, of the Brown Molecular Medicine labs, said that Brown hopes to become a regional center for bio-macromolecular research, which is the study of protein molecules such as DNA and RNA.

In May, his team applied for an $8-million grant from NIH to purchase a new nuclear magnetic-resonance spectrometer, a machine that helps scientists analyze protein structure. Weighing four tons and standing nearly two stories tall, the machine would be larger than anything available in the region, if not the country, Peti said.

Such a powerful tool could help Brown scientists delve more into neurological research such as Parkinson’s disease and cancer research, and attract researchers from throughout New England to use the machine for other studies.

pmarcelo@projo.com