Methanobactin reverses acute liver failure in a rat model of Wilson disease

Lichtmannegger, Josef; Leitzinger, Christin; Wimmer, Ralf; Schmitt, Sabine; Schulz, Sabine; Kabiri, Yaschar; Eberhagen, Carola; Rieder, Tamara; Janik, Dirk; Neff, Frauke; Straub, Beate K.; Schirmacher, Peter; DiSpirito, Alan A.; Bandow, Nathan L.; Baral, Bipin S.; Flatley, Andrew; Kremmer, Elisabeth; Denk, Gerald; Reiter, Florian P.; Hohenester, Simon; Eckardt-Schupp, Friedericke; Dencher, Norbert A.; Adamski, Jerzy; Sauer, Vanessa; Niemietz, Christoph; Schmidt, Hartmut; Merle, Uta; Gotthardt, Daniel; Kroemer, Guido; Weiss, Karl Heinz; Zischka, Hans

doi:10.1172/jci85226

Cited by 135 publications

(112 citation statements)

References 75 publications

(95 reference statements)

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“…Methanobactin, however, was found to bind copper very strongly in a rat model of Wilson disease. Copper was then quickly removed via the bile, and animals treated with methanobactin had sustained clinical recovery (11). Such findings indicate that methanobactin has the potential to be an alternative treatment for Wilson disease, particularly for those patients with acute liver failure (16).…”

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confidence: 99%

“…There is increasing interest in understanding the methanobactin biosynthesis pathway; e.g., it has been recently shown that methanobactin from M. trichosporium OB3b has the potential to treat individuals afflicted with Wilson disease (11)(12)(13). Wilson disease is an autosomal recessive disorder in which the body is unable to correctly assimilate copper, with copper accumulating in the liver and brain, and can result in severe and irreversible damage (14,15).…”

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confidence: 99%

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An Aminotransferase Is Responsible for the Deamination of the N-Terminal Leucine and Required for Formation of Oxazolone Ring A in Methanobactin of Methylosinus trichosporium OB3b

Baral

DiSpirito

et al. 2017

Appl Environ Microbiol

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Gene expression in methanotrophs has been shown to be affected by the availability of a variety of metals, most notably copper-regulating expression of alternative forms of methane monooxygenase. A copper-binding compound, or chalkophore, called methanobactin plays a key role in copper uptake in methanotrophs. Methanobactin is a ribosomally synthesized and posttranslationally modified peptide (RiPP) with two heterocyclic rings with an associated thioamide for each ring, formed from X-Cys dipeptide sequences that bind copper. The gene coding for the precursor polypeptide of methanobactin, mbnA, is part of a gene cluster, but the role of other genes in methanobactin biosynthesis is unclear. To begin to elucidate the function of these genes, we constructed an unmarked deletion of mbnABCMN in Methylosinus trichosporium OB3b and then homologously expressed mbnABCM using a broad-host-range cloning vector to determine the function of mbnN, annotated as coding for an aminotransferase. Methanobactin produced by this strain was found to be substantially different from wild-type methanobactin in that the C-terminal methionine was missing and only one of the two oxazolone rings was formed. Rather, in place of the N-terminal 3-methylbutanoyl-oxazolone-thioamide group, a leucine and a thioamide-containing glycine (Gly-⌿) were found, indicating that MbnN is used for deamination of the N-terminal leucine of methanobactin and that this posttranslational modification is critical for closure of the N-terminal oxazolone ring in M. trichosporium OB3b. These studies provide new insights into methanobactin biosynthesis and also provide a platform for understanding the function of other genes in the methanobactin gene cluster.

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confidence: 99%

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confidence: 99%

An Aminotransferase Is Responsible for the Deamination of the N-Terminal Leucine and Required for Formation of Oxazolone Ring A in Methanobactin of Methylosinus trichosporium OB3b

Baral

DiSpirito

et al. 2017

Appl Environ Microbiol

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“…Moreover, MB bound copper much more avidly than did the other chelators tested and easily navigated mitochondrial entry and exit, mirroring the peptide's cell wall permeability in its native bacterium. MB assessments presented suggest that MB has a favorable safety profile (14), it is possible that unanticipated side effects could emerge in human subjects. Certain individuals are intolerant of D-PA and experience severe side effects, including nephrotoxicity, hematologic abnormalities, and a distinctive skin rash, elastosis perforans serpiginosa.…”

Section: Remaining Questions and Conclusionmentioning

confidence: 99%

“…In this issue, Lichtmannegger, Leitzinger, and colleagues tackle the difficult challenge of medical treatment for advanced WD (14). The authors used a reliable rat model of WD to evaluate the efficacy of a bacterial copper-binding peptide, methanobactin (MB), for the treatment of animals at three progressively worse stages of disease.…”

Section: Methanotroph-derived Copperbinding Protein Shows Promisementioning

confidence: 99%

Microbial peptide de-coppers mitochondria: implications for Wilson disease

Kaler¹

2016

Journal of Clinical Investigation

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C o m m e n t a r y2Walshe's clinical mentor. When Walshe awoke safely in his on-call room the morning after this personal experiment and assessed that "it hadn't killed me," he tested his hypothesis in the patient with WD. A massive increase in urinary copper excretion and clinical improvement were documented in the patient, thereby paving the way for successful treatment of thousands of patients with WD in the decades to follow. Thus, well before the identification of the precise molecular, biochemical, cell biological, and physiological intricacies of WD, copper chelation offered a rational medical treatment (4-7).More advanced stages of WD, which involve severe liver disease or neurological presentations, have, however, been far more difficult to arrest with D-PA or other subsequently developed copper chelators, such as trientine (TETA) and tetrathiomolybdenate (TTM) (8-12). Zinc therapy (8,11,12), an alternative approach based on limiting gastrointestinal absorption of copper via induction of metallothioneins, small cytosolic proteins that sequester copper, has also been unsuccessful in patients with advanced WD. Liver transplantation for WD, which was first performed by T.E. Starzl in Denver in 1975, remains the only curative treatment available for patients in whom the disease has advanced to fulminant hepatic failure (13). While liver transplantation has been successful in the vast majority of WD patients who require it, this procedure carries significant risks, including complications related to surgery and anesthesia and organ rejection or dysfunction, in addition to the potential side effects of a lifelong immunosuppressant drug regimen. Methanotroph-derived copperbinding protein shows promiseIn this issue, Lichtmannegger, Leitzinger, and colleagues tackle the difficult challenge of medical treatment for advanced WD (14). The authors used a reliable rat model of WD to evaluate the efficacy of a bacterial copper-binding peptide, methanobactin (MB), for the treatment of animals at three progressively worse stages of disease. MB is a well-characterized protein produced by the bacterium Methylosinus trichosporium OB3b, which possesses membrane permeability and exceptionally high avidity for copper, the latter via a unique N 2 S 2 -binding site (15). Methane-oxidizing bacteria (methanotrophs), such as M. trichosporium, require large quantities of copper to serve as a cofactor for methane monooxygenase activity; therefore, MB is essential for copper acquisition by these organisms. The severe liver pathology of untreated Wilson disease (WD) is associated with massive copper overload caused by mutations in a liver-specific copper-transporting ATPase, ATP7B. While early, presymptomatic detection and chelation with conventional copper-binding molecules enables effective and life-saving treatment, liver transplantation is the sole option currently available for those with advanced disease. In this issue of the JCI, Lichtmannegger, Leitzinger, and colleagues delineate the therapeutic effect of methanobactin (MB),...

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“…Existing treatments are limited and most have significant side effects, fail to liberate some bound forms of copper, or bind problematic amounts of other biologically relevant metals (97). In a rat model, Mbn reversed the acute liver failure associated with copper overload (98). Mbns or Mbn analogues are thus of significant interest as copper chelating drug candidates.…”

Section: Broader Roles For Mbnsmentioning

confidence: 99%

Methanobactins: Maintaining copper homeostasis in methanotrophs and beyond

Kenney¹,

Rosenzweig

2018

Journal of Biological Chemistry

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Methanobactins (Mbns) are ribosomally produced, post-translationally modified natural products that bind copper with high affinity and specificity. Originally identified in methanotrophic bacteria, which have a high need for copper, operons encoding these compounds have also been found in many non-methanotrophic bacteria. The proteins responsible for Mbn biosynthesis include several novel enzymes. Mbn transport involves export through a multidrug efflux pump and reinternalization via a TonB-dependent transporter. Release of copper from Mbn and the molecular basis for copper regulation of Mbn production remain to be elucidated. Future work is likely to result in the identification of new enzymatic chemistry, opportunities for bioengineering and drug targeting of copper metabolism, and an expanded understanding of microbial metal homeostasis.Transition metals are key cofactors in metabolically important enzymes across all kingdoms of life (1). Nevertheless, careful control of cellular metal levels is required: a cellular surplus can limit viability due to oxidative stress (2), but metal starvation can also be fatal. Investigations of metal influx during conditions of metal scarcity have often been limited to iron, which is poorly bioavailable under aerobic conditions (3). Ironchelating natural products (siderophores) are secreted by many species, and iron from siderophores is incorporated into the cellular iron pool after re-internalization (4). While efflux has historically dominated studies of non-iron homeostasis, there is increasing evidence that similar systems exist for uptake of other metal ions (5, 6).

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Methanobactin reverses acute liver failure in a rat model of Wilson disease

Cited by 135 publications

References 75 publications

An Aminotransferase Is Responsible for the Deamination of the N-Terminal Leucine and Required for Formation of Oxazolone Ring A in Methanobactin of Methylosinus trichosporium OB3b

An Aminotransferase Is Responsible for the Deamination of the N-Terminal Leucine and Required for Formation of Oxazolone Ring A in Methanobactin of Methylosinus trichosporium OB3b

Microbial peptide de-coppers mitochondria: implications for Wilson disease

Methanobactins: Maintaining copper homeostasis in methanotrophs and beyond

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