a form of vitamin K synthesized by bacteria in the intestine or in putrefying organic matter
Also: vitamin K2
Word origin
C20: from me(thyl)-na(phtho)quinone
Examples of 'menaquinone' in a sentence
menaquinone
Eukaryotic cells can synthesize ubiquinone but not menaquinone, whereas prokaryotes can synthesize both quinones.
Dmitry A Ravcheev, Ines eThiele 2016, 'Genomic analysis of the human gut microbiome suggests novel enzymes involved in quinonebiosynthesis', Frontiers in Microbiologyhttp://journal.frontiersin.org/Journal/10.3389/fmicb.2016.00128/full. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The results indicate the safety of menaquinone-7 for human consumption.
Basavaias Ravishankar, Yogesh A. Dound, Dilip S. Mehta, Basti Krishana Ashok, Anselmde Souza, Min-Hsiung Pan, Chi-Tang Ho, Vladimir Badmaev, Ashok D.B. Vaidya 2015, 'Safety assessment of menaquinone-7 for use in human nutrition', Journal of Food and Drug Analysishttp://www.sciencedirect.com/science/article/pii/S1021949814000477. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
These results also confirm our earlier conclusion that demethyl-menaquinone can function in aerobic respiration.
Johan Willem Albertus Van Beilen, Klaas Jan Hellingwerf 2016, 'All three endogenous quinone species of Escherichia coli are involved in controllingthe activity of the aerobic/anaerobic response regulator ArcA', Frontiers in Microbiologyhttp://journal.frontiersin.org/Journal/10.3389/fmicb.2016.01339/full. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The observed bound menaquinone might serve as an additional redox cofactor to mediate the proton-coupled electron transport across the membrane.
Hong-Hsiang Guan, Yin-Cheng Hsieh, Pei-Ju Lin, Yen-Chieh Huang, Masato Yoshimura,Li-Ying Chen, Shao-Kang Chen, Phimonphan Chuankhayan, Chien-Chih Lin, Nai-Chi Chen,Atsushi Nakagawa, Sunney I. Chan, Chun-Jung Chen 2018, 'Structural insights into the electron/proton transfer pathways in the quinol:fumaratereductase from Desulfovibrio gigas', Scientific Reportshttp://link.springer.com/article/10.1038/s41598-018-33193-5. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Based on the blocking of menaquinone pathway, a further 17.7% increase in squalene content was achieved.
Wen Xu, Jia Yao, Lijun Liu, Xi Ma, Wei Li, Xiaojing Sun, Yang Wang 2019, 'Improving squalene production by enhancing the NADPH/NADP+ ratio, modifying the isoprenoid-feedingmodule and blocking the menaquinone pathway in Escherichia coli', Biotechnology for Biofuelshttp://link.springer.com/article/10.1186/s13068-019-1415-x. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)