Peptide deformylase, protein cleaving catalyst

B. Protein-Cleaving Catalyst Selective for Peptide Deformylase / 123... 

The MALDI-TOF MS data indicated that the optimum pH was 7.5. The amount of proteins, such as peak a of Fig. 7, can be estimated fairly accurately by taking the MALDI-TOF MS several times (136). Based on 10 different MALDI-TOF MS measurements, it appeared that about one-half of peptide deformylase was cleaved on incubation with 0.19 equiv of the catalyst for 72 h (Fig. 7), which corresponds to ko of 0.010 h Here, the initial fraction of peptide deformylase complexed with the catalyst cannot exceed 20%. The ko observed when peptide deformylase is fully bound to the catalyst is cat- The lower limit of at is, therefore, estimated as 0.050 h For the myoglobincleaving catalyst Co BU, fecat was 0.022 under the same conditions (126, 127). 

The multiple number of the interactions between CF and peptide deformylase suggested by the simulations experiments accounts for the high selectivity manifested by CF and peptide deformylase. When tested with 15 other proteins, CF did not cleave the proteins. The organic moiety of CF selected from the chemical library containing 15,000 compounds forms a productive complex with peptide deformylase. The Co(III) center of CF appears to be located in a highly productive position in the peptide deformylase-catalyst complex. The high effective molarity of the Co(III) center thus achieved apparently led to effective peptide cleavage. 

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