Structure and function of purified monoclonal antibody dimers induced by different stress conditions.

Purpose: To investigate structure and function of different monoclonal antibody (MAb) dimers.

Methods: MAb dimers were induced by process-related, low pH and UV light stress. Dimers were isolated and purified by chromatography and extensively characterized by biochemical, structural and functional methods.

Electroneutral and electrogenic catalysis by dihaem-containing succinate:quinone oxidoreductases.

Membrane protein complexes can support both the generation and utilization of a transmembrane electrochemical proton potential (Deltap), either by supporting transmembrane electron transfer coupled to protolytic reactions on opposite sides of the membrane or by supporting transmembrane proton transfer. Regarding the first mechanism, this has been unequivocally demonstrated to be operational for Deltap-dependent catalysis of succinate oxidation by quinone in the case of the dihaem-containing SQR (succinate:menaquinone reductase) from the Gram-positive bacterium Bacillus licheniformis. This is physiologically relevant in that it allows the transmembrane Deltap to drive the endergonic oxidation of succinate by menaquinone by the dihaem-containing SQR of Gram-positive bacteria.