LEAKAGE OF PERIPLASMIC PROTEINS FROM ESCHERICHIA-COLI MEDIATED BY POLYMYXIN-B NONAPEPTIDE
LEAKAGE OF PERIPLASMIC PROTEINS FROM ESCHERICHIA-COLI MEDIATED BY POLYMYXIN-B NONAPEPTIDE
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DOI：
10.1128/aac.29.5.781
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发表时间：
1986-05-01
影响因子：
4.9
通讯作者：
CHOPRA, I
中科院分区：
文献类型：
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作者：
DIXON, RA;CHOPRA, I
比较了多粘菌素B和多粘菌素B非肽（PMBN）对大肠杆菌细胞包膜完整性的影响。两种化合物都导致大肠杆菌K-12 3300（pBR322）的蛋白质损失，尽管PMBN释放的蛋白质比多粘菌素b少。释放的蛋白质的来源是通过聚丙烯酰胺凝胶电泳和特定的酶标记（质周β -内酰胺酶，细胞质β -半乳糖苷酶）确定的。这两种化合物释放的蛋白质主要来源于外周质，在多粘菌素B的情况下，伴随着低水平的细胞质蛋白质。虽然多粘菌素B和PMBN都能引起质周蛋白的释放，但化合物释放的单个蛋白不同。质周部分含有6个主要多肽，分子量在62,000（多肽1）和29,000（多肽6）之间。多肽6被鉴定为pbr322编码的β -内酰胺酶，但其他蛋白质未被特异性鉴定。多粘菌素B引起多肽1、2和5的大量释放，多肽4和6也有一些释放。PMBN释放多肽1（痕量）、3、4和6（痕量）。扫描电镜显示，多粘菌素B和PMBN均对大肠杆菌造成表面损伤。然而，多粘菌素B比PMBN产生更大的形态学变化。
The effects of polymyxin B and polymyxin B nonapeptide (PMBN) on cell envelope integrity in Escherichia coli were compared. Both compounds caused loss of proteins from E. coli K-12 3300(pBR322), although PMBN released less protein than did polymyxin B. The origin of the released protein was determined both by polyacrylamide gel electrophoresis and by using specific enzyme markers (beta-lactamase in periplasm, beta-galactosidase in cytoplasm). The proteins released by both compounds were derived principally from the periplasm, accompanied in the case of polymyin B by a low level of cytoplasmic proteins. Although polymyxin B and PMBN both caused release of periplasmic proteins, the individual proteins released by the compounds differed. The periplasmic fraction contained six principal polypeptides with molecular weights between 62,000 (polypeptide 1) and 29,000 (polypeptide 6). Polypeptide 6 was identified as the pBR322-encoded beta-lactamase, but the other proteins were not specifically identified. Polymyxin B caused considerable release of polypeptides 1, 2, and 5 with some release of polypeptides 4 and 6. PMBN released polypeptide 1 (trace), 3, 4, and 6 (trace). Scanning electron microscopy showed that polymyxin B and PMBN both caused surface damage in E. coli. However, polymyxin B produced greater morphological changes than PMBN.