Specific deposition of serum amyloid A protein 2 in the mouse.

The homogenates of amyloid-laden spleens prepared from CBA mice were analysed by SDS-PAGE and immunoblotting employing rat anti-murine monoclonal antibody, MSA 4-26. The results showed that the precursor of amyloid A protein (AA), serum amyloid A protein 2 (SAA2), and SAA intermediates with molecular weights of 10,000, 9000, and 8000 were contained in amyloid-laden tissues. The experiment using sonicated spleen cells and acute phase murine sera showed a delay in the degradation rate of SAA2 on cell fragments and the remains of SAA1 in supernatants. This result can explain disappearance of SAA2 from the murine serum during amyloidogenesis in vivo.