Methyl-coenzyme M reductase

(R)-Sulfolactate dehydrogenase (EC 1.1.1.337), termed ComC, is a member of an NADH/NADPH-dependent oxidoreductase family of enzymes that catalyze the interconversion of 2-hydroxyacids into their corresponding 2-oxoacids. The ComC reaction is reversible and in the biosynthetic direction causes the conversion of (R)-sulfolactate to sulfopyruvate in the production of coenzyme M (2-mercaptoethanesulfonic acid). Coenzyme M is an essential cofactor required for the production of methane by the methyl-coenzyme M reductase complex. ComC catalyzes the third step in the first established biosynthetic pathway of coenzyme M and is also involved in methanopterin biosynthesis. In this study, ComC fromMethanobrevibacter milleraeSM9 was cloned and expressed inEscherichia coliand biochemically characterized. Sulfopyruvate was the preferred substrate using the reduction reaction, with 31% activity seen for oxaloacetate and 0.2% seen forα-ketoglutarate. Optimal activity was observed at pH 6.5. The apparentKMfor coenzyme (NADH) was 55.1 μM, and for sulfopyruvate, it was 196 μM (for sulfopyruvate theVmaxwas 93.9 μmol min−1 mg−1andkcatwas 62.8 s−1). The critical role of ComC in two separate cofactor pathways makes this enzyme a potential means of developing methanogen-specific inhibitors for controlling ruminant methane emissions which are increasingly being recognized as contributing to climate change.

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Anti-Methanogenic Effect of Phytochemicals on Methyl-Coenzyme M Reductase—Potential: In Silico and Molecular Docking Studies for Environmental Protection

Micromachines ◽

10.3390/mi12111425 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1425

Author(s):

Yuvaraj Dinakarkumar ◽

Jothi Ramalingam Rajabathar ◽

Selvaraj Arokiyaraj ◽

Iyyappan Jeyaraj ◽

Sai Ramesh Anjaneyulu ◽

...

Keyword(s):

Molecular Docking ◽

In Silico ◽

Rosmarinic Acid ◽

Docking Studies ◽

Thymus Vulgaris ◽

Piper Betle ◽

Coenzyme M ◽

Dynamics Simulations ◽

Autodock 4.0 ◽

Methyl Coenzyme M Reductase

Methane is a greenhouse gas which poses a great threat to life on earth as its emissions directly contribute to global warming and methane has a 28-fold higher warming potential over that of carbon dioxide. Ruminants have been identified as a major source of methane emission as a result of methanogenesis by their respective gut microbiomes. Various plants produce highly bioactive compounds which can be investigated to find a potential inhibitor of methyl-coenzyme M reductase (the target protein for methanogenesis). To speed up the process and to limit the use of laboratory resources, the present study uses an in-silico molecular docking approach to explore the anti-methanogenic properties of phytochemicals from Cymbopogon citratus, Origanum vulgare, Lavandula officinalis, Cinnamomum zeylanicum, Piper betle, Cuminum cyminum, Ocimum gratissimum, Salvia sclarea, Allium sativum, Rosmarinus officinalis and Thymus vulgaris. A total of 168 compounds from 11 plants were virtually screened. Finally, 25 scrutinized compounds were evaluated against methyl-coenzyme M reductase (MCR) protein using the AutoDock 4.0 program. In conclusion, the study identified 21 out of 25 compounds against inhibition of the MCR protein. Particularly, five compounds: rosmarinic acid (−10.71 kcal/mol), biotin (−9.38 kcal/mol), α-cadinol (−8.16 kcal/mol), (3R,3aS,6R,6aR)-3-(2H-1,3-benzodioxol-4-yl)-6-(2H-1,3-benzodioxol-5-yl)-hexahydrofuro[3,4-c]furan-1-one (−12.21 kcal/mol), and 2,4,7,9-tetramethyl-5decyn4,7diol (−9.02 kcal/mol) showed higher binding energy towards the MCR protein. In turn, these compounds have potential utility as rumen methanogenic inhibitors in the proposed methane inhibitor program. Ultimately, molecular dynamics simulations of rosmarinic acid and (3R,3aS,6R,6aR) -3-(2H-1,3-benzodioxol-4-yl)-6-(2H-1,3-benzodioxol-5-yl)-hexahydrofuro[3,4-c]furan-1-one yielded the best possible interaction and stability with the active site of 5A8K protein for 20 ns.

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Comparison of chemical properties of iron, cobalt, and nickel porphyrins, corrins, and hydrocorphins

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424605000691 ◽

2005 ◽

Vol 09 (08) ◽

pp. 581-606 ◽

Cited By ~ 15

Author(s):

Kasper P. Jensen ◽

Ulf Ryde

Keyword(s):

Density Functional ◽

Hydrolysis Product ◽

Chemical Properties ◽

Coenzyme M ◽

Ring Systems ◽

Reduction Potentials ◽

Higher Spin ◽

Coenzyme F430 ◽

Coenzyme B ◽

Methyl Coenzyme M Reductase

Density functional calculations have been used to compare the geometric, electronic, and functional properties of the three important tetrapyrrole systems in biology, heme, coenzyme B 12, and coenzyme F430, formed from iron porphyrin ( Por ), cobalt corrin ( Cor ), and nickel hydrocorphin ( Hcor ). The results show that the flexibility of the ring systems follows the trend Hcor > Cor > Por and that the size of the central cavity follows the trend Cor < Por < Hcor . Therefore, low-spin Co I, Co II, and Co III fit well into the Cor ring, whereas Por seems to be more ideal for the higher spin states of iron, and the cavity in Hcor is tailored for the larger Ni ion, especially in the high-spin Ni II state. This is confirmed by the thermodynamic stabilities of the various combinations of metals and ring systems. Reduction potentials indicate that the +I and +III states are less stable for Ni than for the other metal ions. Moreover, Ni – C bonds are appreciably less stable than Co - C bonds. However, it is still possible that a Ni – CH 3 bond is formed in F 430 by a heterolytic methyl transfer reaction, provided that the donor is appropriate, e.g. if coenzyme M is protonated. This can be facilitated by the adjacent SO 3− group in this coenzyme and by the axial glutamine ligand, which stabilizes the Ni III state. Our results also show that a Ni III– CH 3 complex is readily hydrolysed to form a methane molecule and that the Ni III hydrolysis product can oxidize coenzyme B and M to a heterodisulphide in the reaction mechanism of methyl coenzyme M reductase.

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