The development of a process for the production of HIV1 gp120 from recombinant cell lines

The HIV1 envelope glycoprotein gpl20 has been expressed in CHO and myeloma cell lines. The glutamine synthetase system was used for gene amplification. After immunopurification, the identity of the 120 kd protein was confirmed by SDS-PAGE, amino-acid analysis, N-terminal sequencing, and antibody and CD4 binding. Some of the purified gpl20 had been specifically cleaved to two disulphide-linked polypeptides. This cleavage was caused by a trypsin-like serine protease, released from the CHO cells possibly as a result of depletion of certain amino-acids. Optimisation of the cell culture process resulted in the production of essentially uncleaved HIV1 gpl20. Authors: Froud, S.J., Clements, G.J., Doyle, M.E., Harris, E.L.V., et al.