Question

what are the domains and subunits of alpha amylase?...both salivary and pancreatic with the functions for each domain and subunit.

Answer 1

what are the domains and subunits of alpha amylase?...both salivary and pancreatic with the functions for each domain and subunit.

Salivary alpha amylase is an enzyme that belongs to the family of glycoside hydrolases. These enzymes can carry out hydrolysis of the aloha 1,4 glycosidic bonds. These consist Of one subunit in which there are 496 amino acid polypeptide chain, that can result in three different domains, A, B as well as C. The size of the gene is almost 10kb and has 10 introns and 11 exons. The salivary alpha amylase consists of a specific tryptophan 58 and 59 residues that helps in starch binding and contributes in the stacking interactions that are present in the binding site.

Pancreatic alpha amylase would be cleaving the alpha 1-4 glycosidic linkage present in a,lose that would yield maltose, denting, maltotriose,. There would be a double displacement mechanism that would help in the anomeric configuration retention. The pancreatic alpha amylase consists of three domains. Domain A is the largest domain, whose active site consists of Asp 197, Glu 233 and asp 300. Domain A helps in ligand interactions with arg 195. There is formation of a parallel beta barrel that consists of eight strands present at the Ce-nter. The smallest is the Domain B, that would serve as the calcium binding site against the beta barrel wall of domain A. Domain c also has anti parallel structures and loosely binds to both the domains.