Absence of synproportionation between oxy and ferryl leghemoglobin. off
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Absence of synproportionation between oxy and ferryl leghemoglobin. off. / Mathieu, C; Swaraj, K; Davies, Michael Jonathan; Trinchant, J C; Puppo, A.
In: Free Radical Research, Vol. 27, No. 2, 08.1997, p. 165-71.Research output: Contribution to journal › Journal article › peer-review
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TY - JOUR
T1 - Absence of synproportionation between oxy and ferryl leghemoglobin. off
AU - Mathieu, C
AU - Swaraj, K
AU - Davies, Michael Jonathan
AU - Trinchant, J C
AU - Puppo, A
PY - 1997/8
Y1 - 1997/8
N2 - The synproportionation reaction between ferryl leghemoglobin and oxyleghemoglobin does not occur, at least under conditions where this process could be clearly demonstrated with myoglobin and hemoglobin. In contrast, a cross synproportionation can occur between oxyleghemoglobin and ferryl myoglobin or between ferryl leghemoglobin and oxymyoglobin. The non-exposure, at the surface of the leghemoglobin molecule, of the nearest tyrosine residue to the heme group could explain this behaviour. Thus leghemoglobin per se does not appear to be able to act as an antioxidant in removing H2O2 by synproportionation. However, in the presence of ascorbate and/or glutathione which can reduce ferryl leghemoglobin, this hemoprotein could act as an H2O2-removing antioxidant, in a process similar to that described for myoglobin. This could also explain why, despite the absence of synproportionation, ferryl leghemoglobin is not detected in nodule extracts.
AB - The synproportionation reaction between ferryl leghemoglobin and oxyleghemoglobin does not occur, at least under conditions where this process could be clearly demonstrated with myoglobin and hemoglobin. In contrast, a cross synproportionation can occur between oxyleghemoglobin and ferryl myoglobin or between ferryl leghemoglobin and oxymyoglobin. The non-exposure, at the surface of the leghemoglobin molecule, of the nearest tyrosine residue to the heme group could explain this behaviour. Thus leghemoglobin per se does not appear to be able to act as an antioxidant in removing H2O2 by synproportionation. However, in the presence of ascorbate and/or glutathione which can reduce ferryl leghemoglobin, this hemoprotein could act as an H2O2-removing antioxidant, in a process similar to that described for myoglobin. This could also explain why, despite the absence of synproportionation, ferryl leghemoglobin is not detected in nodule extracts.
KW - Antioxidants
KW - Ascorbic Acid
KW - Cyclic N-Oxides
KW - Glutathione
KW - Hydrogen Peroxide
KW - Kinetics
KW - Leghemoglobin
KW - Models, Molecular
KW - NADH, NADPH Oxidoreductases
KW - Protein Conformation
KW - Soybeans
KW - Spectrophotometry
KW - Surface Properties
KW - Tyrosine
M3 - Journal article
C2 - 9350420
VL - 27
SP - 165
EP - 171
JO - Free Radical Research
JF - Free Radical Research
SN - 1071-5762
IS - 2
ER -
ID: 138285485