OSTRICH ALPHA-AMYLASE - PURIFICATION AND CHARACTERIZATION OF THE PANCREATIC ISOENZYMES

1. Four ostrich pancreatic alpha-amylase isoenzymes were isolated by i soelectric focusing, following affinity chromatography on cyclohepta-a mylose-Sepharose 4B. 2. Amino acid compositions of the four isoenzymes are very similar with only one charged amino acid (Arg) being signifi cantly different. 3. The molecular weights, as determined by SDS-PAGE and amino acid composition, are nearly identical (52-53 kDa) for all f our isoenzymes. 4. The four alpha-amylase isoenzymes appear to be kine tically distinct enzymes with a requirement for calcium. 5. Ostrich al pha-amylase isoenzymes appear to be non-glycosylated and contain one f ree thiol group.