Transglycosylase and endopeptidase participate in the degradation of murein during autolysis of Escherichia coli
Transglycosylase and endopeptidase participate in the degradation of murein during autolysis of Escherichia coli
复制标题
转糖基酶和内肽酶参与大肠杆菌自溶过程中胞壁质的降解
作者：
K. Kitano;E. Tuomanen;A. Tomasz
对大肠杆菌在头孢定和三氯乙酸引发的自溶过程中释放的细胞壁降解产物进行了分离和表征。胞壁素选择性地从二糖四肽和双二糖四肽组分中损失。两种主要的自溶产物占释放物质的85%以上。化合物1（60至80%的释放物质）是含有1，6-脱水胞壁酸残基的二糖四肽单体。化合物2（释放物质的15至30%）是不含己糖胺的三肽和三四肽的混合物。综上所述，这些结果表明，自溶细胞壁降解在E。大肠杆菌中的酶是选择性的，并且涉及水解转糖基酶和内肽酶的活性。在释放时，至少一些壁组分也暴露于N-乙酰胞壁酸-L-丙氨酸酰胺酶的活性。
The cell wall degradation products released from Escherichia coli during autolysis triggered by cephaloridine or trichloroacetic acid were isolated and characterized. Murein was selectively lost from the disaccharide tetrapeptides and the bisdisaccharide tetrapeptide components. Two major autolytic products accounted for more than 85% of the released material. Compound 1 (60 to 80% of released material) was a disaccharide tetrapeptide monomer containing a 1,6-anhydromuramic acid residue. Compound 2 (15 to 30% of released material) was a mixture of a tritripeptide and a tritetrapeptide without hexosamines. Taken together the findings suggest that autolytic cell wall degradation in E. coli is selective and involves the activity of both the hydrolytic transglycosylase and an endopeptidase. Upon release, at least some of the wall components were also exposed to the activity of the N-acetylmuramic acid-L-alanine amidase.