T. Ogishima et al., ANALYSIS OF ELEMENTS IN THE SUBSTRATE REQUIRED FOR PROCESSING BY MITOCHONDRIAL PROCESSING PEPTIDASE, The Journal of biological chemistry, 270(51), 1995, pp. 30322-30326
We have recently demonstrated that synthetic peptides modeled on the e
xtension peptide of malate dehydrogenase can be a good substrate of mi
tochondrial processing peptidase and that arginine residues present at
positions -2 or -3 and distant from the cleavage point were important
for recognition by the enzyme (Niidome, T., Kitada, S., Shimokata, K.
, Ogishima, T., and Ito, A. (1994) J. Biol. Chem. 269, 24719-24722). W
e further investigated the elements required for substrates of the pro
tease, To analyze the reaction by a more rapid yet quantitative method
, we have developed intramolecularly quenched fluorescent substrates,
Using the fluorogenic substrates we demonstrated that at least one of
the proline and glycine between the distal and proximal arginine resid
ues was also important while other connecting sequences were dispensab
le, In addition, the protease showed considerable preference for aroma
tic and, to a lesser extent, hydrophobic amino acids in the P-1'-posit
ion. These results together with the previous data suggest that the pr
oximal and distal arginine residues, proline and/or glycine between th
em, and P-1' amino acid could be critical determinants for the specifi
c cleavage of the substrates by the protease.