Partial purification and characterization of a novel soybean protease which is inhibited by Kunitz and Bowman-Birk trypsin inhibitors.
A novel serine protease has been partially purified from dry seeds of the soybean (Glycine max) cultivar Keburi by cryoprecipitation at pH 6.4, fractional precipitation with ammonium sulfate, and a series of column chromatographic procedures on DEAE-Sepharose, SP-Sepharose, and Arginine-Sepharose 4B. Some properties of the purified enzyme were studied. The protease hydrolyzed the native storage globulins of soybean seeds, such as the alpha subunit of beta-conglycinin, at a pair of arginine residues, Arg126-Arg127. The proteolysis of the alpha subunit in the purified alpha 2 beta molecule of beta-conglycinin apparently followed first order kinetics. The enzyme was inhibited by both soybean Kunitz trypsin inhibitor and Bowman-Birk proteinase inhibitor in a competitive manner. Moreover, the enzyme could catalyze the specific proteolysis of the A3 polypeptide of the purified G5 glycinin at the Arg99-Gly100 linkage, or the carboxyl side of the Arg98-Arg99 paired basic residues.
Morita
S
S
Central Research Institute, Fuji Oil Co., Ibaraki. moritaj@fujioil.co.jp
Fukase
M
M
Hoshino
K
K
Fukuda
Y
Y
Yamaguchi
M
M
Morita
Y
Y
D000595:Amino Acid Sequence; D052179:Antigens, Plant; D005916:Globulins / Q000302:isolation & purification / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D010455:Peptides; D010940:Plant Proteins / Q000378:metabolism; D055314:Seed Storage Proteins; D012639:Seeds / Q000201:enzymology; D017421:Sequence Analysis; D012697:Serine Endopeptidases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*; D030262:Soybean Proteins; D013025:Glycine max / Q000201:enzymology*; D013696:Temperature; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000494:pharmacology*; D014361:Trypsin Inhibitors / Q000494:pharmacology*
D052179:Antigens, Plant; D005916:Globulins; C053865:Kunitz-type protease inhibitor, plant; D010455:Peptides; D010940:Plant Proteins; D055314:Seed Storage Proteins; D015842:Serine Proteinase Inhibitors; D030262:Soybean Proteins; D014358:Trypsin Inhibitor, Bowman-Birk Soybean; D014361:Trypsin Inhibitors; C013894:beta-conglycinin protein, Glycine max; C093157:glycinin A(3)B(4); D012697:Serine Endopeptidases