TY - JOUR
T1 - Diamide
T2 - An oxidant probe for thiols
AU - Kosower, Nechama S.
AU - Kosower, Edward M.
N1 - Funding Information:
The authors are grateful for the support of their research on thiols and thiol agents by the National Institutes of Health, the United States-Israel Binational Science Foundation, the Israel Academy of Sciences, the Chief Scientist's Office, Israel Ministry of Health, the European Research Office, the Petroleum Research Fund, the J. S. Guggenheim Foundation, and the National Science Foundation.
PY - 1995/1/1
Y1 - 1995/1/1
N2 - The most convenient and chemically simple agent—diamide—is capable of producing a rapid diminution of the tripeptide thiol—glutathione (GSH)—within erythrocytes. An oxidant probe changes the oxidation state of the system; in the present case, diamide is an oxidant probe for thiols and changes the oxidation state of the thiols. Diamide perturbs the thiol status of a system. In most cases, the system can return to its original state by reduction. Information about the role of thiols in the biochemical, biophysical, and physiological economy of a biological system can be gained by the treatment of a system with an oxidant probe for thiols. The reaction of diamide with thiols can be followed spectrophotometrically between 300 and 325 nm and yields a second-order rate constant. The reduction of the diazene forms the diazane dicarboxylic acid bis(N,N-dimethylamide), a hydrazide that does not absorb down to 230 nm. The reaction of thiols with diazenecarbonyl derivatives—such as diamide—occurs in two observable stages, with thiolate anions (RS−) as the reactive species. The reaction proceeds via addition and displacement steps. In the case of GSH, the GS− anion adds to the diazene double bond to form a sulfenylhydrazine, which, in a second step, reacts with a second GS− anion at sulfur to yield a disulfide and a hydrazine.
AB - The most convenient and chemically simple agent—diamide—is capable of producing a rapid diminution of the tripeptide thiol—glutathione (GSH)—within erythrocytes. An oxidant probe changes the oxidation state of the system; in the present case, diamide is an oxidant probe for thiols and changes the oxidation state of the thiols. Diamide perturbs the thiol status of a system. In most cases, the system can return to its original state by reduction. Information about the role of thiols in the biochemical, biophysical, and physiological economy of a biological system can be gained by the treatment of a system with an oxidant probe for thiols. The reaction of diamide with thiols can be followed spectrophotometrically between 300 and 325 nm and yields a second-order rate constant. The reduction of the diazene forms the diazane dicarboxylic acid bis(N,N-dimethylamide), a hydrazide that does not absorb down to 230 nm. The reaction of thiols with diazenecarbonyl derivatives—such as diamide—occurs in two observable stages, with thiolate anions (RS−) as the reactive species. The reaction proceeds via addition and displacement steps. In the case of GSH, the GS− anion adds to the diazene double bond to form a sulfenylhydrazine, which, in a second step, reacts with a second GS− anion at sulfur to yield a disulfide and a hydrazine.
UR - http://www.scopus.com/inward/record.url?scp=0029006990&partnerID=8YFLogxK
U2 - 10.1016/0076-6879(95)51116-4
DO - 10.1016/0076-6879(95)51116-4
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AN - SCOPUS:0029006990
SN - 0076-6879
VL - 251
SP - 123
EP - 133
JO - Methods in Enzymology
JF - Methods in Enzymology
IS - C
ER -