Alpha-glucosidases can be turned on and off, finds study

A study co-led by Simon Fraser University and Purdue University has found that the intestinal enzymes responsible for processing starchy foods can be turned on and off, helping to better control those processes in people with Type 2 diabetes.

The process, called "toggling," was discovered in the lab of SFU V-P Research and chemist Mario Pinto, who has designed inhibitors capable of regulating each of the four starch-digesting enzymes known as alpha-glucosidases. It could lead to several solutions for diabetics and those prone to obesity.

Three of these enzymes are responsible for generating glucose from starch, each in different ways. A fourth enzyme breaks down sucrose, also giving glucose. Occasionally one or more of the enzymes is missing, which also affects how glucose is created, Pinto explains.

"We wanted to determine whether we could control the release of glucose when starch is broken down in the body," says Pinto, whose work included characterizing each of the four enzymes.

Working with a consortium of scientists co-led by Purdue University's Bruce Hamaker, a professor of food science, Pinto says the inhibitors were found to selectively inhibit the enzymes and control starch breakdown.

That means it could be possible to provide the missing enzymes or develop new starches that will digest properly with the enzymes they do have. "It's all about control and using the molecular information we have to control those enzymes," he says.

Their findings have been published in the Journal of Biological Chemistry.

"Selectively inhibiting the enzymes offers the possibility of regulating and directing the release of glucose," says Pinto, noting the consortium of scientists approached the problem from chemical, structural, molecular and cellular perspectives.

The discovery could result in the control of blood glucose for Type 2 diabetes as well as other conditions. When enzymes are missing - a common characteristic of a rare disease known as CSID - Pinto says it may be possible to administer one, and design foods in certain ways that other enzymes can break down.

"This is a powerful piece of knowledge," adds Pinto, noting that in the future it may be possible to control the exact delivery of glucose at different points in the small intestine.