Dwulet F E, Benson M D
J Lab Clin Med. 1987 Sep;110(3):322-9.
Secondary amyloidosis was induced in CBA/J mice by subcutaneous injections of azocasein after priming with amyloid-enhancing factor. Amyloid fibrils were isolated from spleens and the subunit amyloid A (AA) protein purified by gel filtration on a column of Sepharose CL6B. The AA protein was fragmented with trypsin, cyanogen bromide, and Staphylococcus protease, and the peptides were purified by reverse-phase high-performance liquid chromatography. This protein is composed of 73 amino acid residues arranged in a single polypeptide chain with homogeneous amino and carboxyl terminals. Sequence homology with protein AA from other species is quite high with near identity for residues 31 through 54. This sequence is identical to the partial structures for CBA/J mouse AA and serum amyloid A (SAA) previously reported. It is also an exact match to a predicted 73-residue segment from one form of mouse SAA complementary DNA.
在用淀粉样增强因子引发后，通过皮下注射偶氮酪蛋白在CBA/J小鼠中诱导继发性淀粉样变性。从脾脏中分离出淀粉样原纤维，并通过在Sepharose CL6B柱上进行凝胶过滤纯化亚基淀粉样蛋白A（AA）。用胰蛋白酶、溴化氰和葡萄球菌蛋白酶切割AA蛋白，并用反相高效液相色谱法纯化肽段。该蛋白由73个氨基酸残基组成，排列在一条具有均匀氨基和羧基末端的单多肽链中。与其他物种的AA蛋白的序列同源性相当高，31至54位残基几乎完全相同。该序列与先前报道的CBA/J小鼠AA和血清淀粉样蛋白A（SAA）的部分结构相同。它也与一种小鼠SAA互补DNA形式预测的73个残基片段完全匹配。
