title: Physical and catalytic properties of alpha-amylase from Tenebrio molitor L. larvae.
abstract: The amylase from Tenebrio molitor L. larvae (yellow mealworm) was characterized according to a number of its molecular and catalytic properties. The insect amylase is a single polypeptide chain with mol.wt. 68000, an isoelectric point of 4.0 and a very low content of sulphur-containing amino acids. The enzyme is a Ca2+-protein and behaves as an alpha-amylase. Removal of Ca2+ by exhaustive dialysis against water causes the irreversible inactivation of the enzyme. Moreover, the enzyme is activated by the presence in the assay mixture of Cl-, or some other inorganic anions that are less effective than Cl-, and is inhibited by F-. Optimal conditions of pH and temperature for the enzymic activity are 5.8 and 37 degrees C. The insect amylase exhibits an identical kinetic behaviour toward starch, amylose and amylopectin; the enzyme hydrolyses glycogen with a higher affinity constant. Compared with the non-insect alpha-amylases described in the literature, Tenebrio molitor amylase has a lower affinity for starch.
mesh_terms: D000681:Amylases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000688:Amylose / Q000378:metabolism; D000818:Animals; D002118:Calcium; D002712:Chlorides / Q000494:pharmacology; D004789:Enzyme Activation; D005459:Fluorides / Q000494:pharmacology; D007814:Larva / Q000201:enzymology; D008970:Molecular Weight; D013696:Temperature; D013712:Tenebrio / Q000201:enzymology*
chemical_list: D002712:Chlorides; D000688:Amylose; D000681:Amylases; D005459:Fluorides; D002118:Calcium