BIOLOGICALLY RELATED IRON-SULFUR CLUSTERS AS REACTION CENTERS - REDUCTION OF ACETYLENE TO ETHYLENE IN SYSTEMS BASED ON [FE4S4(SR)4]3-

被引:63
作者
MCMILLAN, RS [1 ]
RENAUD, J [1 ]
REYNOLDS, JG [1 ]
HOLM, RH [1 ]
机构
[1] STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305
基金
美国国家科学基金会;
关键词
D O I
10.1016/S0162-0134(00)80019-7
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The possibility that clusters containing the Fe4S4 core unit found in a wide variety of proteins can effect reductive transformations of Fe-S enzyme substrates has been investigated using the reduced synthetic clusters [Fe4S4(SPh)4]3- and acetylene, an alternate nitrogenase substrate. The system [Fe4S4(SPh)4]3-/acetic acid/acetic anhydride in N-methylpyrollidinone at ~25° was found to reduce acetylene homogeneously to ethylene, and in the presence of a deuterium source to afford as the principal stereochemical product cis-1,2-C2H2D2. No appreciable reduction was found using the oxidized cluster [Fe4S4(SPh)4]2-. The system is not catalytic and departs from the strict stoichiometry of the reaction. 2 [Fe4S4(SPh)4]3- + C2H2 + 2H+ → 2 [Fe4S4(SPh)4]2- + C2H4, primarily because of a competing cluster oxidation reaction which could not be eliminated. Based on this reaction ca. 60% conversion of acetylene to ethylene was achieved. A reaction sequence based on absorption and 1H nmr spectral observations and product stereo-chemistry is suggested. The results demonstrate that biologically related, reduced Fe4S4 clusters can effect reduction of at least one Fe-S enzyme substrate, and raise the general possibility of substrate transformation with such clusters as reaction sites in biological systems. © 1979.
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页码:213 / 227
页数:15
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