A joint US-Australian team said it has been able to lay out for the first time in atomic detail how the insulin hormone binds to the surface of cells, triggering the passage of glucose from the bloodstream to be stored as energy.
Lead researcher Mike Lawrence said the discovery, more than 20 years in the making and using powerful x-ray beams, would unlock new and more effective kinds of diabetes medication.
"Until now we have not been able to see how these molecules interact with cells," said Lawrence, from the Walter and Eliza Hall Institute of Medical Research in Melbourne.
"We can now exploit this knowledge to design new insulin medications with improved properties, which is very exciting."
Lawrence said the team's study, published in the latest edition of Nature, had revealed a "molecular handshake" between the insulin and its receptor on the surface of cells.
"Both insulin and its receptor undergo rearrangement as they interact — a piece of insulin folds out and key pieces within the receptor move to engage the insulin hormone," he said of the "unusual" binding method.
Understanding how insulin attaches to cells was key to developing "novel" treatments of diabetes, a chronic condition in which the pancreas does not produce enough insulin or the body cannot use it properly.
"The generation of new types of insulin have been limited by our inability to see how insulin docks into its receptor in the body," Lawrence said.
"This discovery could conceivably lead to new types of insulin that could be given in ways other than injection, or an insulin that has improved properties or longer activity so that it doesn't need to be taken as often."
Importantly, Lawrence said the discovery could also have ramifications for the treatment of diabetes in developing nations, allowing for the creation of more stable insulins that do not need refrigeration.
It could also have applications in the treatment of cancer and Alzheimer's, with insulin playing a role in both diseases, he added.
"Our finding is a fundamental piece of science that ultimately might play across all three of those very serious diseases," Lawrence told AFP.
The Australian Diabetes Council, a lobby group representing people with the condition, said the development was welcome news.
"While we do not currently have a cure for diabetes, discoveries such as this insulin docking breakthrough give us hope that it is coming ever closer," said council chief Nicola Stokes.
Stokes said one Australian was diagnosed with diabetes every five minutes and its prevalence was growing by eight per cent every year, making it the country's fastest-growing chronic disease and biggest health issue.
There are an estimated 347 million diabetes sufferers worldwide and diagnoses are increasing, particularly in developing countries, due to growing levels of obesity and physical inactivity.
It is expected to be the seventh leading cause of death in the world by 2030, with the World Health Organisation projecting total deaths from diabetes will rise by more than 50 per cent in the next 10 years.
Complications of diabetes include heart disease, blindness, limb amputation and kidney failure. — AFP-Relaxnews