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：1974
卷号：71
期号：2
页码：253-256
DOI：10.1073/pnas.71.2.253
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Redox potentials of a menaquinone (MK-6), isolated in earlier researches from two species of the obligately anaerobic genus, Desulfovibrio, as well as two other vitamins K2--menaquinones (MK-5) and (MK-9)-- have been determined polarographically. The measurements have been validated by determination of redox potentials of 1,4-naphthoquinone and vitamin K1 which agree with published potentiometric values. Em7 for menaquinone (MK-6) is -0.067 {+/-} 0.010 V. Redox potentials calculated for terminal acceptor couples currently proposed in the mechanisms of sulfate reduction by Desulfovibrio are consistent with the involvement of menaquinone (MK-6) in at least one of the steps postulated during electron transfer with ultimate production of sulfide.
