Crystalline Pancreatic Amylase. II. Improved Method for its Preparation from Hog Pancreas Glands and Additional Studies of its Properties¹

Abstract

A new procedure for the preparation of crystalline pancreatic amylase from swine is described briefly. The new method offers several distinct advantages over earlier methods reported for the purification and crystallization of pancreatic amylase. The yields of highly active crystalline amylase are materially increased while the new process is much less laborious and much less time consuming than earlier procedures. Additional properties of crystalline pancreatic amylase not previously reported are presented and discussed.

Protein Adsorption to Charged Gold Nanospheres as a Function of Protein Deformability

“…A-Amy is sparingly soluble at pH 7.4 making the concentration of the protein difficult to determine via absorbance at 280 nm, as there are multiple ε values reported in the literature. 34,35 Colorimetric assays have been used to quantify A-Amy by other groups because of this. 36−39 The "standard enhanced protocol" from the Pierce BCA Protein Assay Kit was used to determine the amount of protein in solution.…”

“…The bicinchoninic acid assay is a colorimetric method for determining total protein concentration, and this was used to determine the concentration of A-Amy solutions. A-Amy is sparingly soluble at pH 7.4 making the concentration of the protein difficult to determine via absorbance at 280 nm, as there are multiple ε values reported in the literature. , Colorimetric assays have been used to quantify A-Amy by other groups because of this. − The “standard enhanced protocol” from the Pierce BCA Protein Assay Kit was used to determine the amount of protein in solution. A-Amy solutions were compared to a BSA standard curve spanning 5, 25, 50, 125, and 250 μg/mL (Supporting Information Figure S1).…”

Action patterns of some alpha-type amylases

“…This was a crystalline preparation obtained from Nu tritional Biochemicals Corporation, 21010 Miles Avenue, Cleve land 28, Ohio. They describe the preparation as a 3X crystal lized water suspension, prepared according to the procedure of Caldwell (29).…”

0-(2-hydroxyethyl)-amylose as the substrate of porcine pancreatic [alpha]-amylase action: structural analysis of 0-(2-hydroxyethyl)-maltooligosaccharides

“…The calcium ion functions as a stabilizer against denaturation and proteolysis to maintain the enzyme in the proper configura tion for biological activity (23,24) and acts as a cc-factor necessary for amylolytic activity (16). Improved methods for the preparation of crystalline enzyme were given by Fischer and Bernfeld (25), Caldwell et al (26) and Loyter and Schramm (27). This enzyme was previously reported as a homogeneous enzyme by free boundary electrophoresis and paper electrophoresis (12,20,26) with a molecular weight of 45,000 daltons from sedimentation and diffusion measurements (28).…”

“…Improved methods for the preparation of crystalline enzyme were given by Fischer and Bernfeld (25), Caldwell et al (26) and Loyter and Schramm (27). This enzyme was previously reported as a homogeneous enzyme by free boundary electrophoresis and paper electrophoresis (12,20,26) with a molecular weight of 45,000 daltons from sedimentation and diffusion measurements (28). However, two isoenzymes were isolated by DEAEcellulose chromatography and disc gel electrophoresis (29,30).…”