Chemical reagents of polypeptides side chain: relationships between solubility properties and ability to cross the inner mitochondrial membrane.

The correlation between the solubility properties of DCCD and EDAC (carboxyl specific groups reagents) and AI, NBD-Cl and TNM (tyrosyl specific reagents) and their efficiency to penetrate through the inner mitochondrial membrane, has been done. The penetration of the reagents was evaluated by using their ability to inactivate D-3-hydroxybutyrate dehydrogenase (EC 1.1.1.30) in its natural location, i.e. in intact mitochondria, or in its inverted location, i.e. in inside-out submitochondrial vesicles. For DCCD, AI, NBD-Cl and TNM there is a good correlation between the phase partition in octanol/water and the ability to cross or not the inner mitochondrial membrane. In contrast, there is a discrepancy for EDAC reagent which is hydrophilic, while it significantly inhibits BDH in intact mitochondria. The knowledge of the properties of these reagents can be very useful to locate strategic aminoacid residues in important biological functions.