TY - JOUR
T1 - Mechanism of the cyanide-catalyzed oxidation of α-ketoaldehydes and α-ketoalcohols
AU - Mashino, Tadahiko
AU - Fridovich, Irwin
N1 - Funding Information:
’ This work was supported by research grants from the National Science Foundation, the United States Army Research Office, and the Council for Tobacco Research, USA, Inc. *To whom correspondence should be addressed. a Abbreviations used: MnSOD, the manganese-containing superoxide dismutase; Mn-catalase, the manganese-containing catalase.
PY - 1987/1
Y1 - 1987/1
N2 - Cyanide catalyzes the reduction of dioxygen or of ferricytochrome c by dihydroxyacetone phosphate. The rapid initial phase of these reactions, but not the subsequent slow phase, was augmented by incubating the triose phosphate aerobically or anaerobically at pH 9.0 prior to adding the cyanide. The aerobic incubation, which was most effective, was associated with a decline in enediol, whereas the less effective anaerobic incubation was accompanied by an increase in enediol content. This suggested that the α-ketoaldehyde product of autoxidation of the enediol, rather than the enediol itself, was responsible for the rapid phase reaction which followed addition of cyanide. This was confirmed by exploring the cyanide-catalyzed oxidation of the α-ketoaldehyde, phenylglyoxal. The inhibitory effect of the manganese-containing superoxide dismutase indicated that O2- was a kinetically important intermediate of the rapid phase reaction. A reaction mechanism is proposed which is consistent with the results presented.
AB - Cyanide catalyzes the reduction of dioxygen or of ferricytochrome c by dihydroxyacetone phosphate. The rapid initial phase of these reactions, but not the subsequent slow phase, was augmented by incubating the triose phosphate aerobically or anaerobically at pH 9.0 prior to adding the cyanide. The aerobic incubation, which was most effective, was associated with a decline in enediol, whereas the less effective anaerobic incubation was accompanied by an increase in enediol content. This suggested that the α-ketoaldehyde product of autoxidation of the enediol, rather than the enediol itself, was responsible for the rapid phase reaction which followed addition of cyanide. This was confirmed by exploring the cyanide-catalyzed oxidation of the α-ketoaldehyde, phenylglyoxal. The inhibitory effect of the manganese-containing superoxide dismutase indicated that O2- was a kinetically important intermediate of the rapid phase reaction. A reaction mechanism is proposed which is consistent with the results presented.
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U2 - 10.1016/0003-9861(87)90020-8
DO - 10.1016/0003-9861(87)90020-8
M3 - Article
C2 - 3028255
AN - SCOPUS:0023146553
SN - 0003-9861
VL - 252
SP - 163
EP - 170
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
IS - 1
ER -