Dognin M J, Wittmann-Liebold B
Eur J Biochem. 1980 Nov;112(1):131-51. doi: 10.1111/j.1432-1033.1980.tb04995.x.
Protein L11 was isolated from the 50-S subunit of Escherichia coli ribosomes, using two salt extractions and two chromatographic separations on CM-cellulose. The unusual behavior of the protein when run on sodium dodecyl sulfate electrophoresis showed multiple bands. The complete primary structure of protein L11 is presented in detail. Its sequence was derived from peptides obtained by digesting the protein with trypsin, chymotrypsin, thermolysin, Staphylococcus aureus protease and, after modification, with trypsin. Chemical cleavage was performed with cyanogen bromide. Sequencing of the various peptides was achieved by manual micro-dansyl-Edman degradations and automatic methods. The N-terminal residue of the protein is blocked and was not degradable in the liquid-phase sequenator by the Edman method. It was identified by a combination of enzymatic cleavage and mass spectrometry. Protein L11 contain three methylated amino acid residues, a N alpha-trimethylalanine, and two residues of N epsilon-trimethyllysine. Their behaviour and influence in the sequence elucidation are described. The protein contains 141 amino acid residues and has a molecular weight of 14874. Secondary structure predictions of the protein are given, and its sequence is compared with those of other E. coli ribosomal proteins.
蛋白质L11是从大肠杆菌核糖体的50-S亚基中分离出来的，采用了两次盐提取和两次在CM-纤维素上的色谱分离。该蛋白质在十二烷基硫酸钠电泳中呈现出多条带，表现出异常行为。详细介绍了蛋白质L11完整的一级结构。其序列来自用胰蛋白酶、胰凝乳蛋白酶、嗜热菌蛋白酶、金黄色葡萄球菌蛋白酶消化该蛋白质后得到的肽段，以及经过修饰后再用胰蛋白酶消化得到的肽段。用溴化氰进行化学裂解。通过手动微量丹磺酰-埃德曼降解法和自动方法对各种肽段进行测序。该蛋白质的N端残基被封闭，无法通过埃德曼法在液相测序仪中降解。通过酶切和质谱联用的方法对其进行了鉴定。蛋白质L11含有三个甲基化氨基酸残基，一个Nα-三甲基丙氨酸和两个Nε-三甲基赖氨酸残基。描述了它们在序列解析中的行为和影响。该蛋白质含有141个氨基酸残基，分子量为14874。给出了该蛋白质的二级结构预测，并将其序列与其他大肠杆菌核糖体蛋白的序列进行了比较。
