Limited action of trypsin on porcine pancreatic amylase: Characterization of the fragments

Enzymatic activity of TNB blocked porcine pancreatic amylase

“…Addition of EDTA to amylase promotes a rapid blocking of the SH by these reagents [2-41. In addition EDTA makes the enzyme partially accessible to trypsin [5,6]. Blocking of the 2 SH by the same reagents induces a partial or complete loss of enzyme activity [2-41.…”

The structure of native porcine pancreatic [alpha]-amylase and the purification and properties of the dextransucrases of Streptococcus mutans OMZ 176

“…Most investigators agree the carboxy terminal is a leucine residue (6,22). When the literature concerning the amino terminal is examined^ several different amino acids have been reported: lysine (13); phenylalanine, alanine, and glycine (26); and glycine (27).…”

“…Granger et al (22) have shown that one-half of the PPA in the presence of EDTA can be split with trypsin in 15 min.…”

“…When the literature concerning the amino terminal is examined^ several different amino acids have been reported: lysine (13); phenylalanine, alanine, and glycine (26); and glycine (27). Reports that the amino terminal was derivatized have been made (6,22); a N-acetyl derivative (28,29) and pyroglutamlc acid (30) shows a trypsin and a chymotrypsin-like cleavage (4-2).…”

“…This enzymatically inactive preparation when passed through a Bio-Gel P-100 column gives two peaks, and ^2* contains A and B bound to gether by disulfide bridges and is retarded by the column similar to the way the active amylase is retarded. P]_ con tains the two free sulfhydryls and P2 is the link peptide between A and B (22).…”