Alpha-amylase 1B (AMY1B)

Alpha-amylase 1B (AMY1B) is a calcium-binding enzyme, secreted primarily by the salivary glands, encoding an important isoform of human salivary alpha-amylase. This enzyme initiates the breakdown of dietary starch and glycogen by catalyzing the hydrolysis of internal (1→4)-alpha-D-glucosidic linkages, rapidly reducing starch viscosity and producing maltose and larger oligosaccharides. AMY1B activity varies between individuals, owing to natural genetic variation and copy number differences, with higher copy numbers corresponding to higher enzymatic activity and improved starch digestion efficiency, which has metabolic implications such as lowered obesity risk in some populations. Beyond digestion, salivary alpha-amylase serves as a functional marker for sympathetic nervous system activation during stress and also binds oral bacteria, influencing dental plaque formation and oral health. AMY1B is classified as a glycoside hydrolase enzyme, with principal expression in the salivary gland cytoplasm. While not a major therapeutic target for drug development, it is relevant for research on metabolic health, nutrition, stress physiology, and oral ecology.

Other names

Amylase alpha 1BAMY1BAMY1Alpha-amylase 1B1,4-alpha-D-glucan glucanohydrolase 1Alpha-amylase 1AAmylase alpha 1B (salivary)Amylase, salivary, alpha-1BGlycogenaseSalivary alpha-amylaseSalivary amylase alpha 1B

Inhibition of enzymatic hydrolysis of dietary starch, delaying glucose absorption and moderating postprandial glycemic response.