COVALENT MUREIN-LIPOPROTEIN STRUCTURE OF ESCHERICHIA-COLI CELL WALL - ATTACHMENT SITE OF LIPOPROTEIN ON MUREIN
COVALENT MUREIN-LIPOPROTEIN STRUCTURE OF ESCHERICHIA-COLI CELL WALL - ATTACHMENT SITE OF LIPOPROTEIN ON MUREIN
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DOI：
10.1111/j.1432-1033.1970.tb00936.x
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发表时间：
1970-01-01
期刊：
影响因子：
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通讯作者：
SIEGLIN, U
中科院分区：
文献类型：
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作者：
BRAUN, V;SIEGLIN, U
在链霉蛋白酶处理E. coliB或E. coliK 12（W 945）、赖氨酸和精氨酸保持为与胞壁蛋白（肽聚糖、糖肽）共价结合的唯一氨基酸。这些氨基酸以等摩尔的量存在，每种都等于胰蛋白酶消化胞壁蛋白酶-脂蛋白复合物后保留在胞壁蛋白酶中的赖氨酸的量。从这种胞壁蛋白酶的部分酸水解产物中，通过链霉蛋白酶消化胞壁蛋白酶-脂蛋白复合物制备，已经分离出以下肽：（1）二氨基庚二酰-赖氨酰-精氨酸;（2）丙氨酰-谷氨酰-二氨基庚二酰-赖氨酰-精氨酸;（3）葡糖胺酰-胞壁酰-丙氨酰-谷氨酰-二氨基庚二酰-赖氨酰-精氨酸。肽1显示脂蛋白通过假定的N-末端赖氨酸的α-氨基与二氨基庚二酸的羧基结合。肽2由胞壁蛋白的肽侧链组成，脂蛋白N末端的两个氨基酸赖氨酸和精氨酸与该肽侧链连接。肽3构成了与脂蛋白的赖氨酰-精氨酸肽结合的胞壁素的重复单元。通过短胰蛋白酶消化从胞壁素裂解的脂蛋白具有与未处理的胞壁素-脂蛋白复合物中的脂蛋白相似的氨基酸组成，并且精氨酸作为N末端氨基酸。在胰蛋白酶与细胞壁的快速反应中，酶显然在胞壁蛋白酶-脂蛋白连接的裂解酶的C末端裂解，产生胞壁蛋白酶-赖氨酸和胆固醇-脂蛋白。精氨酸的C末端部分裂解产生游离精氨酸（14%），这些结果支持了先前提出的胞壁蛋白-脂蛋白复合物的超分子结构。平均而言，一个脂蛋白分子共价结合至胞壁蛋白的每十分之一重复单元，由此推导出沿胞壁蛋白的多糖链沿着的两个脂蛋白分子之间的平均距离为103 μ m。
After pronase treatment of the murein‐lipoprotein complex (rigid layer) of the cell wall ofE. coliB orE. coliK12 (W 945), lysine and arginine remain as the sole amino acids covalently bound to the murein (peptidoglycan, glycopeptide). These amino acids occur in equimolar amounts, each equal to the amount of lysine remaining with the murein after trypsin digestion of the murein‐lipoprotein complex.From partial acid hydrolysates of such a murein, prepared by pronase digestion of the mureinlipoprotein complex, the following peptides have been isolated: (1) diaminopimelyl‐lysyl‐arginine; (2) alanyl‐glutamyl‐diaminopimelyl‐lysyl‐arginine; (3) glucosaminyl‐muramyl‐alanyl‐glutamyl‐diaminopimelyl‐lysyl‐arginine. Peptide 1 shows that the lipoprotein is bound by the α‐amino group of the presumbaly N‐terminal lysine to the carboxyl group of diaminopimelic acid. Peptide 2 consists of a peptide side chain of the murein to which the two amino acids of the N‐terminal end of the lipoprotein, lysine and arginine, are attached. Peptide 3 constitutes a repeating unit of the murein to which the peptide lysyl‐arginine of the lipoprotein is bound.The lipoprotein cleaved from the murein by a short trypsin digestion had an amino acid composition similar to the lipoprotein in the untreated murein‐lipoprotein complex and arginine as N‐terminal amino acid. The following structure is proposed: murein‐lysyl‐arginyl‐lipoprotein.In the rapid reaction of trypsin with the cell wall the enzyme apparently cleaves at the C‐terminal end of the lysime of the murein‐lipoprotein linkage which results in murein‐lysine and arginyl‐lipoprotein. Some cleavage at the C‐terminal end of arginine gives rise to free arginine (14%).These results support the supramolecular structure of the murein‐lipoprotein complex previously proposed. On the average one lipoprotein molecule is covalently bound to every tenth repeating unit of the murein from which an average distance of 103 Å between two lipoprotein molecules along the polysaccharide chains of the murein is deduced.