title: Porcine pancreatic alpha amylase and its isoforms--effect of deglycosylation by peptide-N-glycosidase F.
abstract: Porcine pancreatic alpha-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 degrees C towards lower temperature. The fluorescence emission maxima of PPA, PPA-I and PPA-II were found to be 340nm 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.
authors.affiliation: Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Cheluvamba Mansion, Mysore 570020, Karnataka, India.
authors.forename: B Anitha
authors.initials: BA
authors.lastname: Gopal
authors.forename: Sridevi A
authors.initials: SA
authors.lastname: Singh
authors.forename: G
authors.initials: G
authors.lastname: Muralikrishna
mesh_terms: D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D007527:Isoenzymes / Q000378:metabolism; D010179:Pancreas / Q000201:enzymology*; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet; D034421:Sus scrofa; D013696:Temperature; D000516:alpha-Amylases / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D000516:alpha-Amylases; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase