1. Oxygen binding and nitric oxide dioxygenase activity of cytoglobin are altered to different extents by cysteine modification
- Author
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Xiaoping Liu, Aiqin Luo, Craig Hemann, James Boslett, Jay L. Zweier, and Danlei Zhou
- Subjects
0301 basic medicine ,030102 biochemistry & molecular biology ,Cytoglobin ,cytoglobin ,General Biochemistry, Genetics and Molecular Biology ,3. Good health ,Nitric oxide ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,Thioether ,Biochemistry ,Dioxygenase ,Nitric oxide dioxygenase activity ,disulfide bond ,Globin ,NO dioxygenation ,Research Articles ,Oxygen binding ,Research Article ,Cysteine - Abstract
Cytoglobin (Cygb), like other members of the globin family, is a nitric oxide (NO) dioxygenase, metabolizing NO in an oxygen (O2)‐dependent manner. We examined the effect of modification of cysteine sulfhydryl groups of Cygb on its O2 binding and NO dioxygenase activity. The two cysteine sulfhydryls of Cygb were modified to form either an intramolecular disulfide bond (Cygb_SS), thioether bonds to N‐ethylmaleimide (NEM; Cygb_SC), or were maintained as free SH groups (Cygb_SH). It was observed that the NO dioxygenase activity of Cygb only slightly changed (~ 25%) while the P50 of O2 binding to Cygb changed over four‐fold with these modifications. Our results suggest that it is possible to separately regulate one Cygb function (such as O2 binding) without largely affecting the other Cygb functions (such as its NO dioxygenase activity).
- Published
- 2017