期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1983
卷号:80
期号:1
页码:147-150
DOI:10.1073/pnas.80.1.147
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:The sulfur content of N-methylformamide solutions of cofactor from Clostridium pasteurianum nitrogenase has been determined to be 11.9 (+/- 0.9) mol per mol of molybdenum. This number was determined radiochemically, using iron-molybdenum cofactor isolated from molybdenum-iron protein from bacteria grown on 35SO4. A total of 3.2 (+/- 0.2) mol of sulfur per mol of molybdenum was found to be present in cysteine and methionine, probably arising from contaminating proteins not intrinsic to the cofactor. Combined with accumulated evidence that is discussed, these results lead to an updated stoichiometry of MoFe6S8 or 9, not MoFe6S4 as previously thought, for this cluster.