Activity and NMR structure of synthetic peptides of the bovine ATPase inhibitor protein, IF1

The protein IF1 is a natural inhibitor of the mitochondrial FoF1-ATPase.
Many investigators have been propted to identify the shortest segment of
IF1, retaining its native activity, for use in biomedical applications.
Here, the activity of the synthetic peptides IF1-(42-58) and IF1-(22-46)
is correlated to their structure and conformational plasticity determined
by CD and (1H)-NMR spectroscopy. Among all the IF1 segment tested, IF1-(42-
58) exerts the most potent, pH and temperature dependent activity on the
FoF1 complex. The results suggest that, due to its flexible structure, it
can fold in helical and/or b-spiral arrangements tha fovor the binding to
the FoF1 complex, where tha native IF1 binds. IF1-(22-46), instead, as it
adopts a rigid a-elical conformation, it inhibits ATP hydrolysis only in
the soluble F1 mojety.