Search

Lactoperoxidase is an animal protein which participates in antimicrobial mechanisms [I]. Its electron donor profile differs from that of plant peroxidases regarding halide ions [2]. Isolation procedures are available but somewhat tedious [3--S]. Plant isoperoxidases with different affinities for aromatic substrates can be separated on phenylSepharoseR [6]. This observation has now been developed into an isolation procedure for LP. Its essential features are alternations between column materials with ionic and hydrophobic binding forces. The opposite requirements for ionic strength minimize the number of dialyses. The binding of LP to phenyland octyl-Sepharose is compared to the binding of horseradish peroxidase to both Sepharoses. Attempts are made to relate these adsorptions to optically operable equilibria between the peroxidases and free, aromatic ligands. Plant peroxidases can be isolated by means of affinity chromatography on hydroxamic acid-BioGel AR [7]. An imidazolecarrying polysaccharide binds hemoglobin and myoglobin specifically and unspecifically [8]. Sepharose-concanavalin A binds the glycoprotein HRP [9,10].

Carbonylhorseradish peroxidase isoenzyme C2 (EC 1.11.1.7) exhibits two bands in the infrared spectrum attributable to the ligand CO at 1933.5 and 1905 cm−1. Replacement of H2O by D2O results in shifts to both bands to new positions at 1932.5 and 1902.5 cm−1. The results indicate strong hydrogen bonding to the terminal oxygen of CO, of strength comparable to that recently observed for oxyhemoglobin and oxymyoglobin.