Lanthanide-binding peptides and the enzymes that Might Have Been

Lim, Sunghyuk; Franklin, Sonya J.

doi:10.1007/s00018-004-4156-2

Cited by 68 publications

(64 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Uses have emerged for lanthanide-binding pepties beyond those of a simple protein tag [25]. If further applications of LBTs require unavoidable mutations or modifications, it should be noted that certain residues show greater flexibility to variation than others.…”

Section: Results Of Single Mutations At Specific Positionsmentioning

confidence: 99%

Rapid Combinatorial Screening of Peptide Libraries for the Selection of Lanthanide-Binding Tags (LBTs)

et al. 2005

View full text Add to dashboard Cite

Elucidating the structures and functions of novel proteins and their interaction partners is a ubiquitous challenge in laboratories worldwide, escalating the demand for tools for protein study. A small, versatile and multifaceted co-expression tag would therefore be extremely useful to protein scientists: Lanthanide-Binding Tags (LBTs) fulfill such criteria. These tags are remarkably short peptide sequences (15 to 20 residues) comprising only the encoded amino acids; post-expression addition of a lanthanide ion endows the LBTs with the abundant spectroscopic properties of lanthanides. Herein is reviewed a powerful combinatorial screen developed expressly for the synthetic evolution of short calcium-binding motifs into selective, potent binders of terbium and related lanthanide ions. A series of seven libraries resulted in peptides with dissociation constants nearly three orders of magnitude tighter than that of the parent sequence. These libraries utilized two orthogonal linkers on the solid phase support, enabling cleaved peptides to be screened "off-resin", while leaving a portion of the peptide intact on the synthesis resin for later sequencing. Terbium luminescence from the bound LBTs provides the positive selection criterion, and mass spectroscopy using limited capping was implemented for sequence deconvolution. The roles and importance of various residues within the later-generation LBTs are also discussed.

show abstract

Section: Results Of Single Mutations At Specific Positionsmentioning

confidence: 99%

Rapid Combinatorial Screening of Peptide Libraries for the Selection of Lanthanide-Binding Tags (LBTs)

et al. 2005

View full text Add to dashboard Cite

show abstract

“…With the mutant, we can now examine other facets of methanotrophy; e.g., it has been reported that at least some Xox MeDHs are catalytically superior to Mxa MeDH (17,19). This is possible, as lanthanide(III) ions, such as Ce(III), are much stronger Lewis acids than Ca(II) and thus are likely to be much more efficient catalysts for hydrolysis (29). With the mutant, we can now more easily isolate and purify Xox MeDH for kinetic and structural analyses while avoiding possible artifacts resulting from the presence of Mxa MeDH.…”

Section: Discussionmentioning

confidence: 99%

Marker Exchange Mutagenesis of mxaF , Encoding the Large Subunit of the Mxa Methanol Dehydrogenase, in Methylosinus trichosporium OB3b

Haque

DiSpirito

et al. 2016

Appl Environ Microbiol

View full text Add to dashboard Cite

bMethanotrophs have remarkable redundancy in multiple steps of the central pathway of methane oxidation to carbon dioxide. For example, it has been known for over 30 years that two forms of methane monooxygenase, responsible for oxidizing methane to methanol, exist in methanotrophs, i.e., soluble methane monooxygenase (sMMO) and particulate methane monooxygenase (pMMO), and that expression of these two forms is controlled by the availability of copper. Specifically, sMMO expression occurs in the absence of copper, while pMMO expression increases with increasing copper concentrations. More recently, it was discovered that multiple forms of methanol dehydrogenase (MeDH), Mxa MeDH and Xox MeDH, also exist in methanotrophs and that the expression of these alternative forms is regulated by the availability of cerium. That is, expression of Xox MeDH increases in the presence of cerium, while Mxa MeDH expression decreases in the presence of cerium. As it had been earlier concluded that pMMO and Mxa MeDH form a supercomplex in which electrons from Mxa MeDH are back donated to pMMO to drive the initial oxidation of methane, we speculated that Mxa MeDH could be rendered inactive through marker-exchange mutagenesis but growth on methane could still be possible if cerium was added to increase the expression of Xox MeDH under sMMO-expressing conditions. Here we report that mxaF, encoding the large subunit of Mxa MeDH, could indeed be knocked out in Methylosinus trichosporium OB3b, yet growth on methane was still possible, so long as cerium was added. Interestingly, growth of this mutant occurred in both the presence and the absence of copper, suggesting that Xox MeDH can replace Mxa MeDH regardless of the form of MMO expressed. In methanotrophy, the central oxidation pathway of methane is well-known, with methane first being oxidized to methanol by methane monooxygenase (MMO) and methanol further being converted to formaldehyde by methanol dehydrogenase (MeDH). Subsequently, formaldehyde can be combined with either tetrahydrofolate or tetrahydromethanopterin to form methylene tetrahydrofolate and methylene tetrahydromethanopterin, respectively. Methylene tetrahydrofolate can then be assimilated into biomass via the serine cycle. Methylene tetrahydromethanopterin is oxidized to formate, which can be either converted to carbon dioxide via formate dehydrogenase or reduced to methylene tetrahydrofolate. It is speculated that such redundancy for the conversion of formaldehyde exists to control the buildup of this toxic intermediate (1)(2)(3)(4)(5)(6)(7)(8)(9).What is less readily discerned from this simple pathway, however, is that substantial redundancy exists for many steps of the transformation of methane to carbon dioxide and not just the condensation of formaldehyde with either methylene tetrahydrofolate or methylene tetrahydromethanopterin. For example, the first step of methane oxidation (conversion of methane to methanol) can be carried out by two different forms of MMO that are regulated by the availability of copper, i....

show abstract

“…For comparison with early work 21 initial studies used cells grown in batch culture (3 g/L glycerol; 0.67 g/L glycerol 2-phosphate in minimal salts medium). Pre-growth was done from an agar plate into non carbon-limiting medium (3 g/L lactose; 2 days) followed by transfer to lactose-limiting medium (24h; inoculum 5 mL; total volume 100 mL) and 8 aseptic transfer into the chemostat vessel pre-filled with medium. 24 Cells were grown in an air-lift fermenter with minor modifications to a published method.…”

Section: Strains Media and Bacterial Growthmentioning

confidence: 99%

Continuous biocatalytic recovery of neodymium and europium

et al. 2015

View full text Add to dashboard Cite

Batch-grown cells and continuously-grown biofilm of a Serratia sp. were utilized to recover the rare earth elements (REEs) lanthanum and neodymium from solution.Selectivity was obtained for La(III) over Th(IV) using columns of polyacrylamide gelimmobilized cells challenged at a rapid flow rate, exploiting the different solution chemistries and behaviors of REEs(III) and Th(IV). Biofilm-grown cells had a tenfold higher activity of the mediating phosphatase, which promotes metal deposition as the corresponding metal phosphate, reflected as a correspondingly enhanced level of removal of Nd(III) (as NdPO 4 ) in flow-through columns utilizing biofilm on reticulated foam. The biofilms retained activity in the removal of Nd(III) for > 1 year, losing activity exponentially with a half life of 3 months. The flow rate giving 50% removal (FA 1/2 ) of Nd(III) by 3 month old biofilms at pH 5.5 was 272 and 275 mL/h using two independent biofilm preparations, equivalent to a FA 1/2 of 34 column volumes/h for fresh biofilms. The removal of Nd(III) was sustained at pH down to 3.5 with approx. 20% of the column activity lost upon return to pH 5.5. A similar result occurred in the presence of the common REE leaching agent ammonium sulfate (100 mM), this did not affect the ability of Serratia sp. to recover REEs. With a view to the potential for future biomanufacturing of Nd(III)-catalyst, the deposited material was identified as NdPO 4 by X-ray powder diffraction with a nanoparticle size of 14.5 nm, irrespective of the biofilm age.Key phrases: neodymium biorecovery, lanthanum biorecovery, selective rare earth biorecovery, continuous flow process, immobilized Serratia biofilm, nanocrystallite harvest.

show abstract

Lanthanide-binding peptides and the enzymes that Might Have Been

Cited by 68 publications

References 29 publications

Rapid Combinatorial Screening of Peptide Libraries for the Selection of Lanthanide-Binding Tags (LBTs)

Rapid Combinatorial Screening of Peptide Libraries for the Selection of Lanthanide-Binding Tags (LBTs)

Marker Exchange Mutagenesis of mxaF , Encoding the Large Subunit of the Mxa Methanol Dehydrogenase, in Methylosinus trichosporium OB3b

Continuous biocatalytic recovery of neodymium and europium

Contact Info

Product

Resources

About