Discovery advances control of starch digestion

Jun 04, 2010

(PhysOrg.com) -- Controlling diet-induced degenerative disorders such as Type II Diabetes and obesity could be as easy as sprinkling a dietary supplement on your food in the future.

A national research team, including two Simon Fraser University scientists, has chemically mapped the molecular structure of the second of four enzymes in our intestinal lining that are responsible for converting starch into glucose.

SFU chemists Mario Pinto and Sankar Mohan, University of Waterloo biologist David Rose and University of Toronto biochemist Lyann Sim are among six scientists who have just structurally characterized the human sucrase-isomaltase (SI).

They’ve also compared it to maltase-glucoamylase (MGAM), the first starch-digesting enzyme mapped by them about five months ago.

The of the American Society for Biochemistry and Molecular Biology published their latest findings in its June 4 online issue.

Glucose is absorbed into our bloodstream and either converted to energy or fat, depending on the rate of conversion, which is tied to genetics, diet, lifestyle and the microbial flora in our guts.

Too much glucose upsets a critical balance and increases our body’s fat storage rate, a condition that has led to 180 million people developing diabetes worldwide—a number that is expected to double by 2030.

Pinto, SFU’s vp-research, belongs to an international consortium that is analyzing how the activities of starch digesting enzymes, known as intestinal glucosidases, occur in concert and might be altered to control diet-induced degenerative disorders.

“We have two more enzyme activities to characterize,” says Pinto, who credits Mohan, one of his doctoral students, with synthesizing enzyme inhibitors, which were used to characterize the glucosidases.

“We’ve created three dimensional structural models of the glucosidases that have led to the design of new molecules that can selectively turn the glucosidases on and off. One day, these inhibitors could be sprinkled on to food in a powder form to control starch digestion.”

Mohan—who along with SFU postdoctoral fellow Jayakanthan Kumarasamy identified structures in a Sri Lankan plant that inhibit glucosidases—is testing the effectiveness of various iterations of the structures in regulating glucosidases.

Pinto and Mohan will discuss their latest research with colleagues in the international starch digestion consortium at a workshop in Vancouver on June 12 and 13, funded by the Canadian Institutes of Health Research.

Explore further: Chemical biologists find new halogenation enzyme

Provided by Simon Fraser University

4.7 /5 (3 votes)
add to favorites email to friend print save as pdf

Related Stories

Natural plant materials to regulate starch digestion

Jun 16, 2008

Researchers in Switzerland are reporting discovery of natural plant materials that may regulate starch digestion — slowing down the body's conversion of potatoes, rice, and other carbohydrate-rich foods into sugar. The ...

Waistline growth on high-carb diets linked to liver gene

Dec 04, 2007

Experts have been warning for years that foods loaded with high-fructose corn syrup and other processed carbohydrates are making us fatter. Now, a University of Wisconsin-Madison study has uncovered the genetic basis for ...

SEX4, starch and phosphorylation

Jun 26, 2008

Some of the new molecular mechanisms and regulatory components in starch metabolism have been identified by Dr. Samuel Zeeman and his colleagues. Dr. Zeeman, of the Institute of Plant Sciences, ETH Zurich, in Switzerland, ...

Gut feeling: Intestinal germ helps sushi digestion

Apr 07, 2010

Japanese have an easy time digesting sushi and other seaweed-wrapped delicacies thanks in part to an intestinal bacterium that hijacked genes from a marine germ, scientists report on Wednesday.

Recommended for you

Chemical biologists find new halogenation enzyme

14 hours ago

Molecules containing carbon-halogen bonds are produced naturally across all kingdoms of life and constitute a large family of natural products with a broad range of biological activities. The presence of halogen substituents ...

Protein secrets of Ebola virus

20 hours ago

The current Ebola virus outbreak in West Africa, which has claimed more than 2000 lives, has highlighted the need for a deeper understanding of the molecular biology of the virus that could be critical in ...

Protein courtship revealed through chemist's lens

20 hours ago

Staying clear of diseases requires that the proteins in our cells cooperate with one another. But, it has been a well-guarded secret how tens of thousands of different proteins find the correct dancing partners ...

Decoding 'sweet codes' that determine protein fates

22 hours ago

We often experience difficulties in identifying the accurate shape of dynamic and fluctuating objects. This is especially the case in the nanoscale world of biomolecules. The research group lead by Professor Koichi Kato of ...

Conjecture on the lateral growth of Type I collagen fibrils

Sep 12, 2014

Whatever the origin and condition of extraction of type I collagen fibrils, in vitro as well as in vivo, the radii of their circular circular cross sections stay distributed in a range going from 50 to 100 nm for the most ...

User comments : 0