Conus snails produce extremely fast-acting insulin, which they use to paralyse their prey. If suitably modified this molecule may be useful for diabetics.
Conus genus sea snails, mainly found in the waters of Australia, have long been studied for the powerful poisons with which they capture their prey, which are usually small fish, but can also be very dangerous to humans.
As well as actual poisons, some snails, like Conus geographus, also inject special types of insulin into their prey.
These kinds of insulin are so powerful that they cause an immediate and severe drop in blood sugar levels, followed by death, paralysis or disorientation, which allow Conus geographus to capture the fish and then kill and eat it.
So what is lethal for small fish could be very useful, if properly processed, in effectively combating diabetes in humans.
Reducing diabetes levels through a more effective type of insulin
Insulin is produced by the pancreas to lower peaks in blood sugar and to allow cells to use these sugars to create energy. Diabetics no longer produce insulin (type 1 autoimmune diabetes) or produce an inefficient type (type 2 diabetes), so they have to compensate by injecting synthetic insulin-based drugs. However, in some cases the results are not ideal, as the molecule is not always immediately activated.
Obtaining a more effective type of insulin, taking inspiration from sea snails, would be an interesting step in the right direction.
This is the basis of a study published in the scientific journal Nature Chemical Biology, in which researchers from Stanford University, together with colleagues from the University of Utah and the University of Copenhagen, suggest human insulin 'crossed' with that of a type of sea snail - Conus kinoshitai - which appears to ensure an immediate effect.
Back in 2020, the research team managed to create a hybrid insulin from Conus geographus combined with human insulin, but they have now turned their attention to insulin produced by Conus kinoshitai, which has a very different structure to that of Conus geographus, but very similar – and even superior - features and potential.
No aggregates are created
The advantage of this type of insulin is that it does not produce aggregates, as they are called in technical terms, and therefore it is immediately available for use by the body.
What are aggregates? Normally, human insulin is produced and stored in the pancreas until it is needed to control blood sugar levels. To make storage in the pancreas more efficient, individual insulin molecules join together, first in pairs, called dimers, and then in groups of six. The same thing happens with synthetic insulin. These 'clusters' are an obstacle when insulin is injected into a diabetic, and it may not be immediately effective. In short, until the molecules dissociate and become 'single' again, they have difficulty reaching the bloodstream.
This causes a delay that can make it difficult for people with diabetes to keep their blood sugar at optimal levels and increases the risk of complications.
A new way forward
If further studies confirm what researchers have observed so far, insulins from the sea could significantly improve diabetes management, thanks to their ability to be used instantaneously.
“In any case, we have opened up an interesting avenue to develop better therapies for people with diabetes,' confirms biochemist Christopher Hill, a professor at the University of Utah and co-author of the study, proudly.