Model process for removal of caseins from milk of transgenic animals.
We describe a method for selective removal of caseins from milk. The method was developed as a model for transgenic milk processing. Raw cow milk spiked with nonmilk proteins was chosen as the model to resemble transgenic animal milk containing recombinant proteins. The most important elements of the process are (1) "deconstruction" of casein micelles in milk by destroying their Ca(2+) core using a chelating agent (EDTA), thus freeing any protein that might be entrapped in casein aggregates, and (2) "reconstruction" of micelles by providing them with a new Ca(2+) core, thus precipitating them away from the whey proteins, and the protein of interest. Calcium phosphate particles (CAP) were used to reform the disrupted casein micelles. The crystal clear supernatant fraction generated by this method provided >90% recovery and 6- to 13-fold concentration of the desired protein. Product-rich supernatant contained no detectable casein residues, as silver-stained SDS-PAGE and Western blot analyses demonstrated.
Morçöl
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BioSante Pharmaceuticals, Inc., 4600 A&B Highlands Parkway, Smyrna, Georgia 30082, USA. morcol@mindspring.com
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D000818:Animals; D030801:Animals, Genetically Modified; D001709:Biotechnology / Q000379:methods*; D002130:Calcium Phosphates / Q000737:chemistry; D002364:Caseins / Q000302:isolation & purification*; D004492:Edetic Acid / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D007328:Insulin / Q000737:chemistry / Q000235:genetics; D008823:Micelles; D008892:Milk / Q000737:chemistry*; D012709:Serum Albumin / Q000737:chemistry / Q000235:genetics; D012710:Serum Albumin, Bovine / Q000737:chemistry; D000515:alpha 1-Antitrypsin / Q000737:chemistry / Q000235:genetics
D002130:Calcium Phosphates; D002364:Caseins; D007328:Insulin; D008823:Micelles; D012709:Serum Albumin; D000515:alpha 1-Antitrypsin; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D012710:Serum Albumin, Bovine; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; D004492:Edetic Acid; C485829:calcium phosphate, dibasic, anhydrous