The amylase molecule shown in 3-D using Jmol

The human pancreatic amylase molecule consists of 496 amino acid residues - 4204 atoms, ignoring hydrogen atoms but this also includes oxygens from 233 water molecules! (odd single red dots in original view)


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Secondary structure

Cartoon format - a helices red, ß sheets gold
Note especially the central barrel-shaped section through which the substrate presumably passes as it is fed into the active site

Active site

The following amino acid residues have been identified (reference below) as contributing to the conversion of glucose polysaccharides (amylose, starch) into disacccharides (maltose). Interestingly, they all have acidic side-chains (aspartic acid and glutamic acid).

ASP 197 at active site shown as white spacefill
GLU 233 at active site shown as white spacefill
ASP300 at active site shown as white spacefill
glucose dimer (maltose - the product of starch hydrolysis) red and grey
Reference: Subsite mapping of the human pancreatic alpha-amylase active site through structural, kinetic, and mutagenesis techniques. Brayer GD, Sidhu G, Maurus R, Rydberg EH, Braun C, Wang Y, Nguyen NT, Overall CM, Withers SG.

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