Conformational differences between native and recombinant horseradish peroxidase revealed by XXXX planigraphy.

@entity3884 @entity535 @entity3793 @entity273 @entity4463
Significant conformational differences between native and recombinant horseradish peroxidase have been shown by @entity4463 planigraphy, which includes a method of thermal activation of @entity4463 followed by @entity535 analysis of the protein preparation. Comparison of radioactivity distribution among the @entity535 residues with the theoretical (calculated) accessibility shows that the recombinant enzyme is characterized by high hydrophobicity and compactness of folding. The protective role of oligosaccharides in native enzyme has been confirmed. An unexpected result of the study is a finding on high accessibility of a catalytic @entity3793 residue in solution. An effect of low dose (3 Gy) of irradiation on the accessibility of @entity535 residues has been unequivocally demonstrated. The data can be interpreted as swelling of the compact folding and increase in the surface hydrophilicity of the recombinant enzyme. In the case of native enzyme, irradiation does not cause remarkable changes in the accessibility of @entity535 residues indicating the possible extensive radical modification of the native enzyme in the life-course of the cell. The catalytic @entity3793 is an exception. It becomes inaccessible after the enzyme irradiation, while its accessibility in the recombinant enzyme increases. An additional observation of a 5-fold decrease in the rate constant towards @entity273 points to the destructive effect of irradiation on the @entity3884 bond network in the distal domain of the native enzyme molecule and partial collapse of the active site pocket.
