What is alpha glucosidase?

Alpha glucosidase is an enzyme produced in the mammalian intestine. It is not actually secreted into the intestinal tract but rather remains bound to the lining of the small intestine where it interacts with large carbohydrate molecules taken in through the diet. Molecules such as starch, glycogen and other polysaccharides attach to alpha glucosidase and break down into smaller carbohydrates such as glucose and maltose. These small carbohydrates can then be absorbed across the intestinal wall into the blood where they are used as a primary energy source.

Alpha Glucosidase and Diabetes

Alpha glucosidase is one of the enzymes that tends to be produced in excess in diabetics. Obviously, having an excess of the enzyme means that a huge number of large carbohydrate molecules taken in through the diet can be broken down and absorbed – so accounting for the high sugar levels seen in some type 2 diabetics.

To combat this most diabetics take a medication known as an alpha glucosidase inhibitor. These inhibitors attach to the enzyme molecules as they are produced in the intestinal wall. The attachments are irreversible which means the alpha glucosidase molecules are no longer available to bind with the large carbohydrate molecules in the diet and smaller sugars aren’t produced.

Other common uses of Alpha Glucosidase

The enzyme alpha glucosidase is also commonly known as Maltase because of its ability to break down the carbohydrate maltose. Maltose is one of the main ingredients in beer brewing and subsequently maltase is used to create the alcohol content of beer.

During the beer brewing process maltose (alpha glucoside) reacts with water and the enzyme maltase (alpha glucosidase) to produce glucose and alcohol. In this case the enzyme is produced by microorganisms and not by the cells of the human intestine but in many respects the two analogues are exactly the same.

Uses in Science

Being an enzyme, alpha glucosidase has a very definite structure and consequently it will only bind with carbohydrates that have a corresponding structure. This affinity for specific carbohydrate molecules has led to the enzyme being used in carbohydrate structure research the world over.

Recently it has also been used to determine the functionality of a similar enzyme alpha amylase in individuals. Both alpha glucosidase and alpha amylase act on carbohydrates in the small intestine although alpha amylase is produced and secreted by the pancreas. By inhibiting alpha glucosidase, specialists can see how well alpha amylase is performing in an individual, and whether it is being produced in sufficient quantities. If when glucosidase is inhibited there is still an increase in blood sugar levels then it can be said that alpha amylase is present and working as it should. If there isn’t an increase in blood sugar levels then it may indicate a problem with the pancreas.