64 by: Andrea Castro

Student – Andrea Castro

Enzyme Name and E.C number – Sucrase; EC 3.2.1.48.

3: It belongs to the class of hydrolases, enzymes that catalyze the hydrolysis of chemical bonds.

2: It acts on glycosyl compounds, specifically on sugars and their derivatives.

1: It is a glycosidase, meaning it hydrolyzes glycosidic bonds (bonds between carbohydrates or between a carbohydrate and another molecule).

48: This is the specific identifier for sucrase, which hydrolyzes the glycosidic bond in sucrose to release glucose and fructose.

Where is the enzyme found? The sucrase enzyme is primarily found in the small intestine, specifically on the surface of the brush border of the intestinal epithelial cells. These cells have microvilli that increase the surface area for absorption and digestion, and sucrase is one of the enzymes embedded in the membrane of these microvilli.

What does the enzyme do? The sucrase enzyme catalyzes the hydrolysis (breakdown) of the disaccharide sucrose into its two monosaccharide components: glucose and fructose. This is an essential step in carbohydrate digestion, allowing the body to absorb these smaller sugar molecules, which can then be used for energy.

Some interesting and important facts about sucrase:

  1. Sucrase-Isomaltase Complex: Sucrase is part of a larger enzyme complex called sucrase-isomaltase, which also helps break down isomaltose and other oligosaccharides in addition to sucrose.
  2. Sucrase Deficiency: Some individuals have a rare genetic condition called Congenital Sucrase-Isomaltase Deficiency (CSID), leading to the inability to digest sucrose properly. This results in gastrointestinal symptoms like bloating, diarrhea, and gas after consuming sucrose-containing foods.
  3. Essential for Carbohydrate Digestion: Sucrase is crucial for the digestion of table sugar and many sweet foods, providing a direct source of glucose and fructose, both of which are critical for energy metabolism.
  4. Optimal pH: Sucrase works best at a slightly acidic to neutral pH (around 6.0-7.0), which matches the conditions in the small intestine, where digestion primarily takes place.
  5. Dietary Implications: In individuals with sucrase deficiency or sensitivity, reducing sucrose intake or using enzyme replacement therapy (sucrase supplements) can help manage symptoms.

 

References

Gericke, B., Amiri, M., & Naim, H. Y. (2016). The multiple roles of sucrase-isomaltase in the intestinal physiology. Molecular and Cellular Pediatrics3(1). https://doi.org/10.1186/s40348-016-0033-y

Gericke, B., Schecker, N., Amiri, M., & Naim, H. (2017). Structure-function analysis of human sucrase-isomaltase identifies key residues required for catalytic activity. Journal of Biological Chemistry292(26), 11070–11078. https://doi.org/10.1074/jbc.M117.791939

SI gene: MedlinePlus Genetics. (n.d.). Medlineplus.gov. https://medlineplus.gov/genetics/gene/si/

Sucrase – an overview | ScienceDirect Topics. (n.d.). Www.sciencedirect.com. https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/sucrase

The Editors of Encyclopaedia Britannica. (2019). Sucrase | Enzyme. In Encyclopædia Britannica. https://www.britannica.com/science/sucrase

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