Binding of F(ab')/sub 2/ of ANTI-CD3/spl epsiv/ antibody to protein G but not to protein A

The intdon benyeen immunoglobulin and protein G may not be restricted to the Fc portion of antibodies, as many merent F(ab')Z or Fab hgments can also bind to protein G. I found both Fab and F(ab')Z of 145-2C11, a hamster anti-mouse CD~E antibody, bund to a protein Gsepharose. Ink"&, Fab and F(ab")Z of 145-2C11 did not bind to a protein A-sephse. The bin- of Fab and F(abh of 145-2C 11 to protein G provided a usdid method to mnove proteases, chopped hgtnents of the Fc region, and other contarmnatingproteins. ~~g~~iin~e~t~~on ~~be~m~edby~apro teinA-~~se, because the Fab and F(abh portions of 145-2C11 did not bind to a protein Aepharose. The @c be of Fab and F(abh portions of 145-2C11 to a protein Gsepharose but not to a protein A-sepa, and binding of intact 145-2C11 to both protein A- and G-sepharose wiu be useful to develop an &ktive purification protocol for Fab and F(ab')Z portions of 145-2Cll.