Fluoroprolines as Tools for Protein Design and Engineering We thank Mrs. E. Weyher for skillful technical assistance in spectroscopic analyses and Mrs. W. Wenger for her excellent technical assistance in protein preparation. We are indebted to Dr. R. Golbik for providing us with barstar plasmid and protocols for its isolation and purification.

Abstract

The preference of the peptidyl-fluoroproline amide bond for the cis or trans conformation in the model compounds N-acetyl-4-fluoroproline methyl esters fully correlates with the thermostability of the related mutants of the model protein barstar. Thus, the (4S)-L-FPro mutants show a higher and the(4R)-L-FPro mutants a lower thermal stability than barstar.