Rapid release of protease inhibitors from soybeans. Immunochemical quantitation and parallels with lectins

Journal Article · Sun Jan 01 04:00:00 EST 1978 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.61.1.30· OSTI ID:5114617

Hwang, D L ^[1]; Yang, W K; Foard, D E; Lin, K T.D.

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1. Univ. of Tennessee, Oak Ridge

Specific antisera were prepared against the Bowman-Birk trypsin inhibitor and four other trypsin inhibitors of low molecular weight isolated from soybeans. These were used to detect the presence and amount of the inhibitors in: (a) seeds and protein extracts of soybean meal; (b) seedlings; and (c) the water surrounding the seeds and roots of seedlings. Lectin activities in seeds, seedlings, and water were also determined at the same time as the protease inhibitor activities. By competitive inhibition of immunoprecipitation, the combined five low molecular weight protease inhibitors were found to constitute the following percentages of proteins (w/w); 6.3% in defatted soybean meal; 8.1% of the protein extracted from the meal by a buffer of pH 8.6; 8.3, 14.7, 15.2, 16.1, 17.2, and 18.9% of the protein in a lyophilisate of water in which seeds were incubated for 4, 8, 12, 16, 20, and 24 hours, respectively; 8.2% in a lyophilisate of water in which roots of seedlings grew for 20 days; 1.5% in cotyledons; and less than 0.1% in epicotyls, hypocotyls, and roots of 12-day-old seedlings. Hemagglutination activities, expressed as the lowest amount of protein required to give a positive agglutination of 0.2 ml of 2% rabbit red blood cells, were as follows: purified soybean lectin, 0.08 ..mu..g; lyophilisate of water in which seeds were incubated for 4, 8, 12, 16, 20, and 24 hours, 10, 2.5, 5, 5, and 2.5 ..mu..g, respectively; lyophilisate of water in which roots grew for 20 days, 5 ..mu..g; 12-day-old cotyledons, roots, epicotyls, and hypocotyls, 12.5, 100, >1000, and >500 ..mu..g, respectively. The results indicate that a large amount of protease inhibitors as well as lectins are released from seeds during the first 8 hours of imbibition. Neither lima bean trypsin inhibitor (mol wt, 10,000) nor Kunitz soybean trypsin inhibitor (mol wt, 21,500) showed competitive inhibition in tests with antisera against low molecular weight soybean protease inhibitors.

• OSTI ID: 5114617
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 61:1; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

553000* -- Agriculture & Food Technology
60 APPLIED LIFE SCIENCES
AGGLUTININS
BIOCHEMISTRY
BIOMASS
CHEMISTRY
ENERGY SOURCES
ENZYME INHIBITORS
ENZYMES
GLYCINE HISPIDA
HEMAGGLUTININS
HYDROGEN COMPOUNDS
HYDROLASES
IMMUNE SERUMS
LEGUMINOSAE
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PEPTIDE HYDROLASES
PLANT TISSUES
PLANTS
PROTEINS
RENEWABLE ENERGY SOURCES
ROOTS
SEEDLINGS
SEEDS
TRYPSIN
WATER