What does dextransucrase do?
Dextransucrase is a glucosyltransferase (E. C. 2.4. 1.5) that catalyzes the transfer of glucosyl residues from sucrose (S) to dextran polymer and liberates fructose (F) according to the following equation (8): n S → n F + dextran (glucose)n.
What is the substrate for the enzyme Dextransucrase?
Thus, the two substrates of this enzyme are sucrose and (1,6-alpha-D-glucosyl)n, whereas its two products are D-fructose and (1,6-alpha-D-glucosyl)n+1. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases.
Where does this molecule specifically bind to the enzyme?
The molecules that an enzyme works with are called substrates. The substrates bind to a region on the enzyme called the active site. There are two theories explaining the enzyme-substrate interaction. In the lock-and-key model, the active site of an enzyme is precisely shaped to hold specific substrates.
Is dextran a polymer?
Dextran is a polymer of anhydroglucose. It is composed of approximately 95% alpha-D-(1-6) linkages. The remaining a(1-3) linkages account for the branching of dextran. Conflicting data on the branch lengths implies that the average branch length is less than three glucose units.
Which enzyme is chemically not a protein?
RNA molecules are also known as ribozymes. These RNA molecules are enzymes that are not composed of proteins.
How do enzymes catalyse chemical reactions?
To catalyze a reaction, an enzyme will grab on (bind) to one or more reactant molecules. These molecules are the enzyme’s substrates. In some reactions, one substrate is broken down into multiple products. In others, two substrates come together to create one larger molecule or to swap pieces.
Is dextran a protein?
Dextran is a complex polysaccharide derived from bacteria and it consists of glucose subunits. Dextran, not only seems to possess antithrombotic properties, but it also forms scaffolds that are resistant to protein and cell adhesion.
Is ribosome an enzyme?
Ribosomes are large and complex enzymes: the simplest ribosomes from bacteria have a mass of some 2.5 million Da. All ribosomes consist of two loosely associated subunits of unequal size.
Why all enzymes are proteins but not all proteins are enzymes?
Only few proteins have the capability to bind the substrate with the help of their active sites in such a manner that allows the reaction to take place in an efficient manner. Hence, all enzymes are proteins but all proteins are not enzymes.
What is denaturing and what causes it to occur?
If a protein loses its shape, it ceases to perform that function. The process that causes a protein to lose its shape is known as denaturation. Denaturation is usually caused by external stress on the protein, such as solvents, inorganic salts, exposure to acids or bases, and by heat.
What is the structure of dextransucrase?
Dextransucrase (sucrose: 1,6-α-D-glucan 6-α -D-glucosyltransferase, EC 220.127.116.11) polymerizes the glucosyl moiety of sucrose to form dextran, an α-1→6 linked glucan with α-1→2, α-1→3, or α-1→4 branch linkages depending on the producing enzyme.
Is k1-r derived from soluble dextransucrase?
The cell-associated dextransucrase produced by sucrose-grown cells of cariogenic Streptococcus mutansK1-R is derived from soluble dextransucrase.
What is the difference between α-glucans and dextrans?
Dextrans are a type of α-glucans which are comprised of a polymeric chain of glucosyl units and that are synthesized by dextransucrase by acceptor reaction. The polysaccharides, especially α-glucans and β-glucans, serve as potential immunostimulator, immunomodulator and anticancer agents.
Can dextran be used to treat cancer?
In vitro cytotoxicity analysis of dextran showed that it displayed anticancer activity against cervical cancer (HeLa) and colon cancer (HT29) cell lines which might be due to the ability of dextran to modify membrane surface proteins in tumor cells, leading to adhesion disturbances ( Shukla and Goyal, 2013 ).