Effect of substitution of glycine for arginine at position 146 of the A1 subunit on biological activity of Escherichia coli heat-labile enterotoxin
Open Access
- 1 May 1988
- journal article
- research article
- Published by American Society for Microbiology in Journal of Bacteriology
- Vol. 170 (5), 2208-2211
- https://doi.org/10.1128/jb.170.5.2208-2211.1988
Abstract
The ADP-ribosyltransferase activity of polypeptide A1 of cholera toxin and that of Escherichia coli heat-labile enterotoxin (LT) are primarily responsible for the toxic activities of these toxins. Since the amino acid sequences of the two A1 polypeptides are very similar, their functional mechanisms are considered to be the same. Arg-146 of polypeptide A1 is thought to be involved in the active site, because this amino acid of cholera toxin has been identified as the site of self-ADP-ribosylation. However, the exact role of Arg-146 and the significance of self-ADP-ribosylation in toxicity remain unclear. We substituted Arg-146 of polypeptide A1 of LT with Gly by oligonucleotide-directed mutagenesis and examined the biological property of the resultant mutant LT. The substitution changed the mobility of subunit A on sodium dodecyl sulfate-polyacrylamide gel but did not reduce the vascular permeability activity of LT. This result indicates that Arg-146 is not absolutely required for toxic activity and that LT can express its toxic activity without self-ADP-ribosylation at Arg-146.This publication has 48 references indexed in Scilit:
- Bacterial Protein Toxins with Latent ADP‐Ribosyl Transferases ActivitiesPublished by Wiley ,1986
- Strategies and Applications of in Vitro MutagenesisScience, 1985
- ADP-RIBOSYLATIONAnnual Review of Biochemistry, 1985
- Evolution and structure of two ADP‐ribosylation enterotoxins, Escherichia coli heat‐labile toxin and cholera toxinFEBS Letters, 1984
- Location and amino acid sequence around the ADP-ribosylation site in the cholera toxin active subunit A1Biochemical and Biophysical Research Communications, 1983
- ADP-ribosyl transferase activity of cholera toxin polypeptide A1 and the effect of limited trypsinolysisBiochemical and Biophysical Research Communications, 1981
- Prediction of protein antigenic determinants from amino acid sequences.Proceedings of the National Academy of Sciences, 1981
- The arrangement of subunits in chlorea toxinBiochemistry, 1976
- Electrophoretic analysis of the major polypeptides of the human erythrocyte membraneBiochemistry, 1971
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970