Preparation of F(ab′)2 fragments from mouse IgG of various subclasses☆

Abstract We have investigated the effects of peptic digestion on mouse monoclonal immunoglobulins of each subclass of IgG. F(ab′) 2 fragments were obtained in good yield from IgG1, IgG2a and IgG3 proteins. The relative rates of digestion were IgG3 > IgG2a > IgG1. Variations in rate of digestion were noted for individual monoclonal IgG3 proteins. Five different IgG2b proteins were degraded very rapidly without the detectable formation of antigen-binding F(ab′) 2 fragments. One IgG1 protein out of four tested was also rapidly degraded.