The Integral and Extrinsic Bioactive Proteins in the Aqueous Extracted Soybean Oil Bodies

Abstract

Soybean oil bodies (OBs), naturally pre-emulsified soybean oil, have been examined by many researchers owing to their great potential utilizations in food, cosmetics, pharmaceutical, and other applications requiring stable oil-in-water emulsions. This study was the first time to confirm that lectin, Gly m Bd 28K (Bd 28K, one soybean allergenic protein), Kunitz trypsin inhibitor (KTI), and Bowman-Birk inhibitor (BBI) were not contained in the extracted soybean OBs even by neutral pH aqueous extraction. It was clarified that the well-known Gly m Bd 30K (Bd 30K), another soybean allergenic protein, was strongly bound to soybean OBs through a disulfide bond with 24 kDa oleosin. One steroleosin isoform (41 kDa) and two caleosin isoforms (27 kDa, 29 kDa), the integral bioactive proteins, were confirmed for the first time in soybean OBs, and a considerable amount of calcium, necessary for the biological activities of caleosin, was strongly bound to OBs. Unexpectedly, it was found that 24 kDa and 18 kDa oleosins could be hydrolyzed by an unknown soybean endoprotease in the extracted soybean OBs, which might give some hints for improving the enzyme-assisted aqueous extraction processing of soybean free oil.

Do lipids influence the allergic sensitization process?

“…The association of Gly m Bd 30K with oil bodies was critical for the enhanced absorption of intact and digested fragments of Gly m Bd 30K in mice through a fat carrier–mediated transport 22 . Gly m Bd 30K forms a complex through a disulfide bond with another important soy allergen, Gly m 5, which, together with Gly m 6, is associated with oil bodies isolated from soy 23 . The association with oil bodies might protect these allergens from digestion and allow an increased cellular uptake through carrier-mediated transport, but further studies need to elucidate this aspect.…”

Effect of Oleosins on the Stability of Oil Bodies in Soymilk

“…3. In the oil bodies derived from soybeans soaked for 1 or 20 h and from soymilk, clear bands were observed at the 24-kDa and 18-kDa regions; these were identified as oleosins (Herman, 1987;Zhao et al, 2013) and the electrophoresis patterns of the three oil bodies were highly similar. According to a previous report (Chen and Ono, 2010a), there were no differences in the SDS-PAGE patterns and surface hydrophobicity of unheated and heated oil bodies.…”

Recovering proteins from potato juice by complexation with natural polyelectrolytes

“…Protein samples were prepared following the report described by Zhao et al . (). In the final step before MALDI‐TOF/TOF‐MS analysis, 0.7 μL of each sample and 0.7 μL of 4‐hydroxy‐α‐cyanocinnamic acid (used as a matrix) were pipetted on a MALDI target and air‐dried, respectively.…”