One of the simple sugars galactose or mannose used in this e

One of the simple sugars (galactose or mannose) used in this exercise should have inhibited Con A-peroxidase binding to cheek epithelial cells and the Con A-induced hemoagglutination reaction. Name this sugar and describe the mechanism by which it inhibits these effects. Describe the mechanism responsible for the Con-A induced hemoagglutinating reaction. Most membrane proteins including the Con-A receptor can be solubilized by treating cell membranes with a non-ionic detergent such as Triton X 100. You are given such a soluble preparation of erythrocyte proteins. Describe a single procedure that could be used to isolate the Con A Receptor from this preparation.

Solution

1.Mannose is the sugar molecule.The mechanism by which mannose inhibits this reaction is via competitive inhibition. Mannose occupies the mannose-binding site on Con A by binding to it.Since the mannose binding site of Con A is already occupied,it will not be able to bind to receptors containing carbohydrate residues on the RBCs of cheek epithelial cell surface and thus inhibits hemoagglutination reaction.

2.ConA or Concanavalin A Concanavalin A interacts receptors present on outer membrane of RBCs known as glycocalyx.Glycocalyx consists of glycoprotein polysaccharide and ConA binds to these polysaccharides and causes clumping of RBCs or hemoagglutination.

3.Affinity column chromatography can be used to separate Con A receptor from soluble preparation of erythrocyte by using carbohydrates that are embedded in the column.ConA receptors will bind to carbohydrates in the column and will be retained while other receptor proteins will elute out first.The retained ConA receptors can be eluted out using glycine-hydrochloride buffer at pH 3.0.