The Covalent Murein‐Lipoprotin Structure of the Escherichia coli Cell Wall

作者：Volkmar Braun, Uta Sieglin · 发表于：European Journal of Biochemistry · 年份：1970 · DOI：10.1111/j.1432-1033.1970.tb00936.x · 被引用次数：218 · 研究领域：Advanced Proteomics Techniques and Applications、Bacterial Genetics and Biotechnology、RNA and protein synthesis mechanisms

After pronase treatment of the murein‐lipoprotein complex (rigid layer) of the cell wall of E. coli B or E. coli K12 (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 apparent...