Perhaps you should try some spelling variations:
"post-posttranslational modification" » "post-posttranslational modifications", "post-translational modifications"
"post-translational modification" » "post-translational modifications"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("post-translational modification") OR ("post-posttranslational modification")).
• Removing quotes may allow a broader search: (( post-translational modification ) or ( post-posttranslational modification )).
• Adding a wildcard symbol may retrieve word variants: (("post-translational modification") or ("post-posttranslational modification"))*.