Life Sciences Commons^™

Bovine Muscle Cathepsin D: Purification And Proteolytic Activity On Muscle Proteins, Paul Hwaleun Fan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An affinity column for cathepsin D was prepared making use of the strong affinity of pepstatin for cathepsin D. Pepstatin is an N-acylated pentapeptide from Actinomycetes with the following structure: isovaleryl-L-valyl-L-valyl-4-amino-3-hydroxy-6-methylheptanoyl-L-alanyl-4-amino-3-hydroxy- 6-methyl heptanoic acid. A relatively rapid and efficient method for cathepsin D purification has been developed; Steps include homogenization, ammonium sulfate fractionation, and chromatography on pepstatin-Sepharose column. The final preparation has a specific activity of 38 units/mg. and shows a single protein band on polyacrylamide gel electrophoresis in sodium dodecyl sulfate corresponding to a subunit molecular weight of 42,000. Polyacrylamide gel electrophoresis studies did not reveal any impurities. The …