title: Identification of a new soybean kunitz trypsin inhibitor mutation and its effect on bowman-birk protease inhibitor content in soybean seed.
abstract: Soybean seed contains antinutritional compounds that inactivate digestive proteases, principally corresponding to two families: Kunitz trypsin inhibitors (KTi) and Bowman-Birk inhibitors (BBI). High levels of raw soybean/soybean meal in feed mixtures can cause poor weight gain and pancreatic abnormalities via inactivation of trypsin/chymotrypsin enzymes. Soybean protein meal is routinely heat-treated to inactivate inhibitors, a practice that is energy-intensive and costly and can degrade certain essential amino acids. In this work, we screened seed from 520 soybean accessions, using a combination of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblots with anti-Kunitz trypsin inhibitor antibodies. A soybean germplasm accession was identified with a mutation affecting an isoform annotated as nonfunctional (KTi1), which was determined to be synergistic with a previously identified mutation (KTi3-). We observed significant proteome rebalancing in all KTi mutant lines, resulting in dramatically increased BBI protein levels.
authors.affiliation: United States Department of Agriculture - Agricultural Research Service, University of Missouri-Columbia , 205 Curtis Hall, Columbia, Missouri 65211, United States.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Gillman
authors.forename: Won-Seok
authors.initials: WS
authors.lastname: Kim
authors.forename: Hari B
authors.initials: HB
authors.lastname: Krishnan
mesh_terms: D000595:Amino Acid Sequence; D008969:Molecular Sequence Data; D009154:Mutation; D012639:Seeds / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013025:Glycine max / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000235:genetics / Q000378:metabolism*; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D014358:Trypsin Inhibitor, Bowman-Birk Soybean; D014360:Trypsin Inhibitor, Kunitz Soybean
keywords: Bowman−Birk inhibitor; Kunitz trypsin inhibitor; seed composition improvement; soybean