Precursor in cotranslational secretion of diphtheria toxin.
نویسندگان
چکیده
By extracellular labeling of peptides of intact Corynebacterium diphtheriae, followed by fractionation of the cells and chain completion by isolated polysomes, it is shown that diphtheria toxin is formed and secreted cotranslationally by membrane-bound polysomes; free polysomes from none. Moreover, when the chains on these polysomes were completed in vitro, in the absence of membrane they were found to include not only diphtheria toxin of a molecular weight of 62,000, but also a larger precursor of a molecular weight of 68,000. The precursor was identified by several properties: immune precipitation; conversion into toxin fragments A and B; adenosine diphosphate ribosyl-transferase activity after activation with trypsin; and cleavage to 62,000 daltons by membrane enzymes. The precursor yields an N-terminal A fragment with a broadened molecular weight distribution, compared with that from authentic toxin, thus supporting the expectation that the extra segment of the precursor is N-terminal.
منابع مشابه
Cotranslational secretion of diphtheria toxin and alkaline phosphatase in vitro: involvement of membrane protein(s).
Crude messenger ribonucleic acid fractions isolated from Corynebacterium diphtheriae and Escherichia coli were translated in an E. coli in vitro protein-synthesizing system and yielded precursors of the secreted proteins diphtheria toxin and alkaline phosphatase, respectively. Addition of inverted E. coli inner membrane vesicles to the system during the initial stages of translation resulted in...
متن کاملDesign and Production of Recombinant TAT Protein Structure, Catalytic Domain of Diphtheria Toxin, and Evaluation of Its Effect on Cell Line
Background and Objectives: Cancer is one of the most deadly diseases in the present age and its conventional therapies have had low success. Toxin therapy of cancer is a new therapeutic approach, which has attracted the attention of pharmaceutical specialists. Diphtheria toxin consists of three functional, transducing, and binding domains, that the functional part inhibits protein synthesis and...
متن کاملShort Communication: Diphtheria Toxin Repressor (dtxR) Gene-based Genetic Diversity of Corynebacterium diphtheriae isolated in Jakarta, Indonesia, 2018-2019
Background and Objective: In Indonesia, diphtheria cases caused by Corynebacterium diphtheriae are still occurring until today. One of the causes is probably the diphtheria toxin repressor (dtxR) gene which influences toxin expression. Therefore, in this study the characterization of the gene was performed to determine the mutations that affect the DtxR protein. Methods: The dtxR genes of ...
متن کاملInterleukin 4/Diphtheria Toxin Gene Leukemia in Mice Using Cytotoxic T Cells Transduced with an Retroviral Immunotoxin Gene Therapy of Acute Myelogenous
The potential benefit of immunotoxin (IT) for cancer therapy has mostly been limited by the fact that only a small portion of injected dose ever reaches the cancer target. Thus, we set out to determine whether antigen-specific CTLs would be suitable vehicles to deliver IT to the site of cancer cells in vivo. A retroviral vector was constructed for gene therapy with (interleukin 4) IL-4 position...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Journal of bacteriology
دوره 141 1 شماره
صفحات -
تاریخ انتشار 1980