2 4 6 trinitrobenzenesulfonic acid sol tnbs

Low temperature defatted soybean meal, a soybean byproduct prepared by oil immersion at a low temperature, was purchased from Harbin High-Tech Co. (Harbin, China). Ascorbic acid, ethylene diaminetetraacetic acid (EDTA), 5,5′-dithiobis (2-nitrobenzoic acid) (DTNB), and 2,4,6-trinitrobenzenesulfonic acid sol (TNBS) were purchased from Sigma Chemical Co. (St. Louis, MO, USA). The β-conglycinin ELISA kit was purchased from Crodibio Co. (Quanzhou, China). All chemicals and reagents obtained in this study were of analytical grade.

Maize starch with a M_w of 3.788 × 10⁷ g/mol was acquired from Huanglong Food Industry Co., Ltd. (Changchun, China). Thermostable a-amylase (AA) was bought from Novozymes Co., Ltd. (Bagevaerd, Denmark). Dimethyl sulphoxide (DMSO, chromatography degree) was obtained from Honeywell Burdick & Jackson (USA). N,N′-Carbonyldiimidazole (CDI) and spermine were purchased from Aladdin Reagent Company (Shanghai, China). Fetal bovine serum (FBS), RPMI-1640, penicillin-streptomycin, trypsin and PBS (pH = 7.4) were purchased from Hyclone Co. (Carlsbad, CA, USA). Methylthiazolyldiphenyl-tetrazolium bromide (MTT) and 2,4,6-trinitrobenzenesulfonic acid sol (TNBS) were obtained from Sigma Chemical Co. (St. Louis, MO, USA). Lipofectamine 2000 reagent was purchased from Invitrogen (Carlsbad, CA, USA). The plasmid pAcGFP1-C1 (4.7 kb; Clontech, Palo Alto, CA, USA) encoding enhanced green fluorescent protein (EGFP) was maintained and propagated in DH5αstrain of E.coli, and then purified by using the Endfree plasmid kit (Tiangen, China). The purity and concentration of plasmids were determined by UV spectrophotometry (A260/A280). All other reagents used in this experiment were of analytical grade and used without further treatment.