Purification and partial characterization of α-Amylase allozymes from the lesser grain borer, Rhyzopertha dominica

摘要: Abstract α-Amylase was purified from adults of the lesser grain borer, Rhyzopertha dominica (F.), by ammonium sulfate precipitation, glycogen complex formation, and gel filtration chromatography. Specific activity increased 16 AU/mg protein in crude extract to 705 final sample (1 AU = 1 mg maltose hydrate/min at 30°C). Two major bands, active starch zymograms, were present R m 0.71 0.79 when examined polyacrylamide electrophoresis (PAGE) on 7.5% gels. In addition, several minor proteins that had α-amylase also present. Molecular masses two allozymes estimated be 57 55 kDa under dissociating conditions. Isoelectric points pH 3.4 3.5. The amylases most 7 presence 20 mM NaCl resulted a 10.7-fold increase V max . K for soluble 0.127%. Saline extracts wheat (“Florida 302”) 2- 3-fold more inhibitory weight basis towards R. than prepared cultivars triticale, “Morrison” “CT-4161”, respectively. Interaction inhibitors wheat, inhibitor-0.28 inhibitor-0.19 family isoinhibitors, with α-amylases studied. Complex formation between demonstrated PAGE, although protein-protein complexes formed not completely stable during electrophoresis. i values 2.6 nM 2.9 inhibitor-0.19. Binding these as tight compared interaction Sitophilus weevils Tenebrio molitor