TY - JOUR
T1 - Topography of human cytochrome b5/cytochrome b5 reductase interacting domain and redox alterations upon complex formation
AU - Samhan-Arias, Alejandro K.
AU - Almeida, Rui M.
AU - Ramos, Susana
AU - Cordas, Cristina M.
AU - Moura, Isabel
AU - Gutierrez-Merino, Carlos
AU - Moura, José J.G.
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2018/2
Y1 - 2018/2
N2 - Cytochrome b5 is the main electron acceptor of cytochrome b5 reductase. The interacting domain between both human proteins has been unidentified up to date and very little is known about its redox properties modulation upon complex formation. In this article, we characterized the protein/protein interacting interface by solution NMR and molecular docking. In addition, upon complex formation, we measured an increase of cytochrome b5 reductase flavin autofluorescence that was dependent upon the presence of cytochrome b5. Data analysis of these results allowed us to calculate a dissociation constant value between proteins of 0.5 ± 0.1 μM and a 1:1 stoichiometry for the complex formation. In addition, a 30 mV negative shift of cytochrome b5 reductase redox potential in presence of cytochrome b5 was also measured. These experiments suggest that the FAD group of cytochrome b5 reductase increase its solvent exposition upon complex formation promoting an efficient electron transfer between the proteins.
AB - Cytochrome b5 is the main electron acceptor of cytochrome b5 reductase. The interacting domain between both human proteins has been unidentified up to date and very little is known about its redox properties modulation upon complex formation. In this article, we characterized the protein/protein interacting interface by solution NMR and molecular docking. In addition, upon complex formation, we measured an increase of cytochrome b5 reductase flavin autofluorescence that was dependent upon the presence of cytochrome b5. Data analysis of these results allowed us to calculate a dissociation constant value between proteins of 0.5 ± 0.1 μM and a 1:1 stoichiometry for the complex formation. In addition, a 30 mV negative shift of cytochrome b5 reductase redox potential in presence of cytochrome b5 was also measured. These experiments suggest that the FAD group of cytochrome b5 reductase increase its solvent exposition upon complex formation promoting an efficient electron transfer between the proteins.
KW - Autofluorescence
KW - Cytochrome b
KW - Cytochrome b reductase
KW - Dissociation constant
KW - Redox potential
UR - http://www.scopus.com/inward/record.url?scp=85034043564&partnerID=8YFLogxK
U2 - 10.1016/j.bbabio.2017.10.005
DO - 10.1016/j.bbabio.2017.10.005
M3 - Article
C2 - 29111436
AN - SCOPUS:85034043564
SN - 0005-2728
VL - 1859
SP - 78
EP - 87
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
IS - 2
ER -