Patent ID: 8574883

Claim:
A method of co-extracting multiple proteins from chicken egg white, comprising steps of: (1) diluting fresh egg white with 20˜100 mmol/L NaCl solution of an equal volume, mixing, and adjusting pH to 5.0˜8.0, so as to obtain processed egg white diluted solution; (2) adding polyethylene glycol-8000 (PEG-8000) to the egg white diluted solution while stirring, until the mass percentage concentration of the PEG-8000 is 2˜6%, fully stirring for 2˜12 hours, and then processing by centrifugation to obtain precipitate A and supernatant A, continually adding PEG-8000 to the supernatant A until the mass percentage concentration of the PEG-8000 is 8˜12%, fully stirring for 2˜12 hours, then processing by centrifugation to obtain precipitate B and supernatant B, and continually adding PEG-8000 to the supernatant B until the mass percentage concentration of the PEG-8000 is 14˜18%, fully stirring for 2˜12 hours, then processing by centrifugation to obtain precipitate C and supernatant D; (3) suspending the precipitate A in a 200800 mmol/L NaCl solution, stirring for 4˜24 hours followed by centrifugation to obtain new precipitate, suspending the new precipitate in distilled water, fully stirring, centrifuging, suspending in distilled water again and processing centrifugation again, so as to wash away sodium chloride, collecting a precipitate, so as to obtain ovomucin; (4) separating the precipitate B, the precipitate C and the supernatant D individually by Q Sepharose Fast Flow anion-exchange chromatography, processing stepwise elution through sodium chloride solution, respectively collecting, dialyzing, and then freeze-drying each eluted peak to obtain multiple protein products to be identified; and (5) identifying the multiple protein products to be identified by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), pooling protein products of a same kind, so as to obtain lysozyme, ovotransferrin and ovalbumin.