The plot of fractional enzyme activity versus extent of protein modification, for cases where all enzyme modifiable groups of a certain kind are essential for activity, is found to be nearly independent of the number, per enzyme active site, of modifiable groups involved. Such plots usually, by a fallacious extension of the initial portion of the plot on the extent-of-modification axis, are interpreted to mean the modification of one single group per enzyme active site (or per enzyme molecule). The possible relevance of these findings to cases in the literature is discussed.

This content is only available as a PDF.
You do not currently have access to this content.