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Determination of affinities of lanthanide-binding proteins using chelator-buffered titrations

Journal Article · · Methods in Enzymology
 [1];  [2];  [2]
  1. Pennsylvania State Univ., University Park, PA (United States); The Pennsylvania State University
  2. Pennsylvania State Univ., University Park, PA (United States)

The recent discoveries of the first proteins that bind lanthanides as part of their biological function not only are relevant to the emerging field of lanthanide-dependent biology, but also hold promise to revolutionize the technologically critical rare earths industry. Although protocols to assess the thermodynamics of metal–protein interactions are well established for “traditional” metal ions in biology, the characterization of lanthanide-binding proteins presents a challenge to biochemists due to the lanthanides' Lewis acidity, propensity for hydrolysis, and high-affinity complexes with biological ligands. These properties necessitate the preparation of metal stock solutions with very low buffered “free” metal concentrations (e.g., femtomolar to nanomolar) for such determinations. Here in this paper we describe several protocols to overcome these challenges. First, we present standardization methods for the preparation of chelator-buffered solutions of lanthanide ions with easily calculated free metal concentrations. We also describe how these solutions can be used in concert with analytical methods including UV–visible spectrophotometry, circular dichroism spectroscopy, Förster resonance energy transfer (FRET), and sensitized terbium luminescence, in order to accurately determine dissociation constants (Kds) of lanthanide–protein complexes. Finally, we highlight how application of these methods to lanthanide-binding proteins, such as lanmodulin, has yielded insights into selective recognition of lanthanides in biology. We anticipate that these protocols will facilitate discovery and characterization of additional native lanthanide-binding proteins, will motivate the understanding of their biological context, and will prompt their applications in biotechnology.

Research Organization:
Pennsylvania State Univ., University Park, PA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC0021007
OSTI ID:
1781338
Journal Information:
Methods in Enzymology, Journal Name: Methods in Enzymology Vol. 651; ISSN 0076-6879
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (69)

Structural Origin of the High Affinity of a Chemically Evolved Lanthanide-Binding Peptide journal July 2004
Essential and Ubiquitous: The Emergence of Lanthanide Metallobiochemistry journal August 2019
Determination of Iron in Solutions with the Ferric–Xylenol Orange Complex journal September 1999
Absorptiometric study of the chelates formed between the lanthanoids and xylenol orange journal September 1968
PQQ-dependent methanol dehydrogenases: rare-earth elements make a difference journal May 2014
Rare earth elements in soil and plant systems - A review journal December 2004
Lanthanides: New life metals? journal June 2016
Differential ultraviolet spectra of insulin journal January 1956
Tyrosyl-carboxylate ion hydrogen bonding in ribonuclease journal January 1957
Complexometric titration of yttrium and the lanthanons—IA comparison of direct methods journal November 1963
Investigation of equilibria in solution. Determination of equilibrium constants with the HYPERQUAD suite of programs journal October 1996
Hyperquad simulation and speciation (HySS): a utility program for the investigation of equilibria involving soluble and partially soluble species journal April 1999
Techniques for measuring cellular zinc journal December 2016
The biochemistry of lanthanide acquisition, trafficking, and utilization journal January 2021
How to study proteins by circular dichroism journal August 2005
Molecular structure of La3+-induced methanol dehydrogenase-like protein in Methylobacterium radiotolerans journal May 2011
Molecular structure and gene analysis of Ce3+-induced methanol dehydrogenase of Bradyrhizobium sp. MAFF211645 journal June 2011
Method for Accurate Determination of Dissociation Constants of Optical Ratiometric Systems: Chemical Probes, Genetically Encoded Sensors, and Interacting Molecules journal November 2013
Structural Basis for Rare Earth Element Recognition by Methylobacterium extorquens Lanmodulin journal October 2018
Bioadsorption of Rare Earth Elements through Cell Surface Display of Lanthanide Binding Tags journal February 2016
Selective and Efficient Biomacromolecular Extraction of Rare-Earth Elements using Lanmodulin journal July 2020
Influence of a Heterocyclic Nitrogen-Donor Group on the Coordination of Trivalent Actinides and Lanthanides by Aminopolycarboxylate Complexants journal January 2018
Implementing f-Block Metal Ions in Medicine: Tuning the Size Selectivity of Expanded Macrocycles journal June 2019
Engineered PQQ-Dependent Alcohol Dehydrogenase for the Oxidation of 5-(Hydroxymethyl)furoic Acid journal June 2020
The Chemistry of Lanthanides in Biology: Recent Discoveries, Emerging Principles, and Technological Applications journal August 2019
From Antenna to Assay: Lessons Learned in Lanthanide Luminescence journal April 2009
Tyrosine and tyrosinate fluorescence of bovine testes calmodulin: calcium and pH dependence journal March 1984
Kinetic studies show that calcium and terbium have different binding preferences toward the four calcium-binding sites of calmodulin journal December 1984
Characterization of lanthanide(III) ion binding to calmodulin using luminescence spectroscopy journal November 1985
Solution Structure of the Paramagnetic Complex of the N-Terminal Domain of Calmodulin with Two Ce3+ Ions by 1H NMR, journal September 1997
Fluorescent Sensors for Measuring Metal Ions in Living Systems journal March 2014
Binding constants for neodymium(III) and samarium(III) with human serum transferrin journal June 1986
Fluorescence quenching of the indole ring system by lanthanide ions journal September 1974
On the Mechanism of Fluorescence Quenching. Tyrosine and Similar Compounds journal February 1964
Lanthanide ion probes of structure in biology. Laser-induced luminescence decay constants provide a direct measure of the number of metal-coordinated water molecules journal January 1979
Probing Site-Specific Calmodulin Calcium and Lanthanide Affinity by Grafting journal March 2005
Calcium Ion Gradients Modulate the Zinc Affinity and Antibacterial Activity of Human Calprotectin journal October 2012
Functional Synthetic Model for the Lanthanide-Dependent Quinoid Alcohol Dehydrogenase Active Site journal January 2018
Lanmodulin: A Highly Selective Lanthanide-Binding Protein from a Lanthanide-Utilizing Bacterium journal October 2018
A Selective, Protein-Based Fluorescent Sensor with Picomolar Affinity for Rare Earth Elements journal February 2019
Affinity gradients drive copper to cellular destinations journal May 2010
Optimized ratiometric calcium sensors for functional in vivo imaging of neurons and T lymphocytes journal January 2014
Measuring calcium signaling using genetically targetable fluorescent indicators journal August 2006
Rare earth element alcohol dehydrogenases widely occur among globally distributed, numerically abundant and environmentally important microbes journal April 2019
Gene products and processes contributing to lanthanide homeostasis and methanol metabolism in Methylorubrum extorquens AM1 journal July 2020
Open questions on the environmental chemistry of radionuclides journal November 2020
Challenges to achievement of metal sustainability in our high-tech society journal January 2014
Biological, biomolecular, and bio-inspired strategies for detection, extraction, and separations of lanthanides and actinides journal January 2020
Taking advantage of luminescent lanthanide ions journal January 2005
The challenges of determining metal–protein affinities journal January 2010
Circularly permuted green fluorescent proteins engineered to sense Ca2+ journal March 2001
Siderocalin-mediated recognition, sensitization, and cellular uptake of actinides journal August 2015
Tight and specific lanthanide binding in a de novo TIM barrel with a large internal cavity designed by symmetric domain fusion journal November 2020
Uptake and effect of rare earth elements on gene expression in Methylosinus trichosporium OB3b journal May 2016
The Hill equation revisited: uses and misuses. journal September 1997
Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides journal September 1976
Rare earth metals are essential for methanotrophic life in volcanic mudpots: Rare earth metals essential for methanotrophic life journal September 2013
Metal-Binding Properties of Calmodulin journal May 1982
Use of rare‐earth elements in the phyllosphere colonizer Methylobacterium extorquens PA1 journal February 2019
Rare earth elements: Mendeleev’s bane, modern marvels journal January 2019
Metals and Methanotrophy journal January 2018
Pyrroloquinoline Quinone Ethanol Dehydrogenase in Methylobacterium extorquens AM1 Extends Lanthanide-Dependent Metabolism to Multicarbon Substrates journal August 2016
Lanthanide-Dependent Regulation of Methanol Oxidation Systems in Methylobacterium extorquens AM1 and Their Contribution to Methanol Growth journal February 2016
Functional Role of Lanthanides in Enzymatic Activity and Transcriptional Regulation of Pyrroloquinoline Quinone-Dependent Alcohol Dehydrogenases in Pseudomonas putida KT2440 journal June 2017
The PedS2/PedR2 Two-Component System Is Crucial for the Rare Earth Element Switch in Pseudomonas putida KT2440 journal August 2018
Spectrophotometric Determination of Cerium(III) and Some Rare Earths with Xylenol Orange journal October 1962
A Catalytic Role of XoxF1 as La3+-Dependent Methanol Dehydrogenase in Methylobacterium extorquens Strain AM1 journal November 2012
Lanthanide-Dependent Methanol Dehydrogenases of XoxF4 and XoxF5 Clades Are Differentially Distributed Among Methylotrophic Bacteria and They Reveal Different Biochemical Properties journal June 2018
MxaY regulates the lanthanide-mediated methanol dehydrogenase switch in Methylomicrobium buryatense journal January 2016