Porcine pancreatic alpha amylase and its isoforms—Effect of deglycosylation by peptide-N-glycosidase F

Porcine pancreatic α-amylase (PPA) and its isoforms (PPA-I and PPA-II) were deglycosylated by peptide-N-glycosidase F (PNGase F) to investigate the role of bound carbohydrate. On deglycosylation, the effect on thermal stability was less pronounced. Deglycosylation resulted in a shift of the mid-point of thermal transition by 1–2 °C towards lower temperature. The fluorescence emission maxima of PPA, PPA-I and PPA-II were found to be 340 nm indicating the presence of tryptophan residues in a fairly hydrophilic environment. A red shift in emission spectra accompanied by an increase in fluorescence intensity was observed upon deglycosylation.