Potential of primate monoclonal antibodies to substitute for human antibodies: nucleotide sequence of chimpanzee Fab fragments.

The nucleotide sequence of the mRNA that codes for Fab fragments from two chimpanzee monoclonal antibodies has been determined. Both antibodies have high affinity and good specificity for digoxin. Four domains from the two antibodies have been sequenced: the constant domains of the kappa and lambda light chains, the variable domain of the lambda light chain, and the CH1 domain of the IgG1 heavy chain. There are very few differences between the chimpanzee and human sequences; the nucleotide sequences differ by less than 2%.