Site-specific mutagenesis of the catalytic subunit of cholera toxin: substituting lysine for arginine 7 causes loss of activity. |
| |
| Authors: | W N Burnette V L Mar B W Platler J D Schlotterbeck M D McGinley K S Stoney M F Rohde H R Kaslow |
| |
| Affiliation: | Amgen Inc., Thousand Oaks, California 91320. |
| |
| Abstract: | Cholera and pertussis toxins each contain a subunit with ADP-ribosyltransferase activity, sharing a region of nearly identical amino acid sequence near the NH2 terminus. Previous investigations have shown that substitution of a lysine residue for Arg-9 in the catalytic A subunit of pertussis toxin substantially eliminates its enzyme activity. We now report that substitution of lysine for the position-equivalent Arg-7 of cholera toxin subunit A leads to a similar loss of catalytic activity. This result suggests a correlation of function with structure between the sequence-related cholera and pertussis toxin A subunits and may contribute to the design of a vaccine containing an enzymatically inert analog of cholera toxin. |
| |
| Keywords: | |
|
