Proteomic characterization of soybean seed hull for biotechnological purposes

LAUTARO BRACCO; ALEXANDRA TARGOVNIK; M. V. MIRANDA; CASCONE

Santiago de Compostela

Congreso; XII EUPA Congress; 2018

Spanish Proteomics Society (SEProt) and the Portuguese Proteomics Association (ProCura),

Background: soybean crop has a huge development. Its consumption is led by oil and flour, for which the hull must be removed. Hull contains valuable proteins that can be extracted prior to pellet it. The aim of this work is the proteomic characterization of soybean seed hull, as a way to identify candidate proteins for downstream processing, allowing the revaluation of soybean crop. Methods: hulls were extracted with phosphate buffer pH 6.9. The extract was centrifuged and concentrated further by ultrafiltration (10X). Then it was reduced with dithiothreitol, alkylated with iodoacetamide and digested with trypsin. Peptides were extracted with acetonitrile and analyzed by nano-HPLC-ESI-Orbitrap. Data analysis was performed with Proteome Discoverer. The protein-protein association network was performed using STRING. Gene Ontology analysis was performed using QuickGo. Relative abundance was estimated by Peptide Spectrum Matches (PSM) and by Exponentially Modified Protein Abundance Index (emPAI). Results: a total of 149 proteins were identified. The interactomic map contains 401 interactions. Proteins were classified by their cellular location (membrane: 32%; cytoplasm: 15%; extracellular region: 10%; nucleus: 6%; cell wall: 5%; endoplasmic reticulum: 4%; cytosol: 3%; others: 7%; n.a.: 18%), by their molecular functions (catalytic activity: 47%; nucleotide binding: 11%; metal ion binding: 11%; others 17%; n.a.: 13%), and by biological processes (metabolic process: 55%; response to stimulus: 14%; regulation of biological process: 4%; transport: 4%; biogenesis: 4%; others: 8%; n.a.: 11%). Approximately 60 proteins with biotechnological applications were identified, of which 15 were selected by its high relative abundance: Glucan 1,3-β-Glucosidase, Glycinin (G1, G2 and G4), Trypsin inhibitor, Protein disulfide-isomerase, Cysteine proteinase, Beta-amylase, β-D-xylosidase, 2S Albumin, Peroxidase, Lectin, GDSL esterase/lipase, Thioredoxin, Chitinase and Lipid transfer protein. 10 proteins were identified as allergens. Conclusions: high-value proteins of biotechnological interest, express