Abstract
Alpha-amylase of amniotic fluid was studied with the pH titration curve method using the conventional enzyme active staining. Four clear amylase bands, which have different isoelectric points ranging from 4.9 to 6.5, were recognized on 5% polyacrylamide gel. Three bands of them had the same isoelectric point of deamidated salivary alpha-amylase bands, but did not clearly change their isoelectric points after neuraminidase treatment. Under continuous pH range, the affinity electrophoresis was also performed by combination with this method. Main alpha-amylase band of amniotic fluid, similar to that of saliva, showed higher affinity to the ligand than that of pancreas.
