Recombination of Univalent Subunits Derived from Rabbit Antibody

SUMMARY Univalent 3.5 S fragments of rabbit antibody have been re- combined in good yield by oxidation to give 5 S protein that again has the capacity to form specific precipitates. The fragments were prepared by successive treatments of specifically purified antiovalbumin or antibovine gamma globulin with pepsin and 0.01 M mercaptoethylamine at 37”. The sedimentation co- efficient after reoxidation was almost identical to that observed before reduction, suggesting that the reconstituted antibody is bivalent. Upon reduction of the recombined material, break- down to -3.5 S occurs once again. The amino acid composition of the 5 S protein formed by peptic digestion is consistent with previous evidence indicating that this fragment consists es- sentially of Porter’s fractions I and II. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. REFERENCES PORTER, R. R., Nature, 182, 670 (1958).