Lipid-binding properties of TRIM72

Abstract

TRIM72 is known to play a critical role in skeletal muscle membrane repair. To better understand the molecular mechanisms of this protein, we carried out an in vitro binding study with TRIM72. Our study proved that TRIM72 binds various lipids with dissociation constants (K(d)) ranging from 88.2 ± 9.9 nM to 550.5 ± 134.5 nM. In addition, the intrinsic fluorescence of TRIM72 exponentially decreased when the protein was diluted with stirring. The time-resolved fluorescence decay occurred in a concentration- independent manner. The fluorescence-decayed TRIM72 remained in its secondary structure, but its binding properties were significantly reduced. The dissociation constants (K(d)) of fluorescence-decayed TRIM72 for palmitate and stearate were 159.1 ± 39.9 nM and 355.4 ± 106.0 nM, respectively. This study suggests that TRIM72 can be dynamically converted by various stimuli. The results of this study also provide insight into the role of TRIM72 in the repair of sarcolemma damage.