when mixtures of the two nontoxic mutant proteins , enzymically active crm ( 45 ) protein and enzymically inactive crm ( 197 ) protein , are subjected to mild treatment with trypsin in the presence of a thiol and then allowed to reoxidize after dialysis to remove excess thiol , `` '' diphtheria toxin '' '' is reconstituted in high yield .
C1564139
mutant proteins
C0033684
protein