The BC3H1 smooth muscle cells of mice brain, BC3H1 is a permanent cell line derived from a mouse brain tumor. When these cells become quiescent, they express the muscle form of creatine phosphokinase, myokinase, the nicotinic acetylcholine receptor, as well as smooth muscle a-actin, all indicative of a muscle phenotype. This is important in relation to the activity of membrane proteins, because losing the activity of such systems will ultimately lead to malfunction or death of the cell. The interactions of Serum Amyloid A (SAA) and Serum Amyloid A protofibrils with BC3H1 cells of the mouse are dealt with in detail to study the binding of SAA protofibrils in various onditions. The induced fluorescence, induced circular dichroism, FACScan and MTT assay results have shown the SAA and SAA prototfibrils binding and cell toxicity with the BC3H1 cells with different concentrations of alphaB-Crystallin 0.15-15 nM. Specifically, cells were incubated with 1.25-6.25 M SAA-FITC and SAA protofibrils-FITC assayed. The 50% viable BC3H1 cells at 4–6 M with an LD50 of 3.5 M. The interaction of serum amyloid A fibrils with a cell surface binding site/receptor might alter the local environment to cause cellular dysfunction and to be more favorable for amyloid formation. In the present study, concluding that the SAA fibrils and SAA protein binding and cell cytotoxicity was reduced in the presence of alphaB-Crystallin.
