Protective Effects of Covalent Cross-Linking on Proteolysis of Human Coproporphyrinogen Oxidase and Implications for Porphyria
Ahmed W. Jafri, Jason R. Stephenson, Justin B. Morgenthaler, Jon A. Friesen and Marjorie A. Jones
DOI : 10.3844/ajbbsp.2008.442.449
American Journal of Biochemistry and Biotechnology
Volume 4, Issue 4
The effects of covalent cross-linkers on the enzyme, coproporphyrinogen oxidase, had been previously studied but their role in protecting the enzyme from protease cleavage has not been evaluated. Therefore, we examined how the cross-linker bis (sulfosuccinimidyl) suberate (BS3) affects the ability of trypsin to digest purified, wild type recombinant human coproporphyrinogen oxidase and selected mutants. Following incubation, the apparent molecular weights of peptides were evaluated by SDS-PAGE and enzymatic activity was assessed by spectroscopy following HPLC. For both wild type and mutants, the results indicated that the cross-linker was indeed able to protect against trypsin digestion relative to the enzyme incubated with trypsin in the absence of the cross-linker. These data have implications for the episodic nature of porphyria.
© 2008 Ahmed W. Jafri, Jason R. Stephenson, Justin B. Morgenthaler, Jon A. Friesen and Marjorie A. Jones. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.