Special Issue "Nuclear Magnetic Resonance Spectroscopy"

A special issue of Magnetochemistry (ISSN 2312-7481).

Deadline for manuscript submissions: closed (31 October 2017)

Special Issue Editor

Guest Editor
Dr. Teresa Lehmann

Department of Chemistry, University of Wyoming, Laramie, WY 82071, USA
Website | E-Mail
Phone: +1 307 766 2772
Fax: +1 307 766 2807
Interests: NMR; cancer drugs; malaria; solution structure determination; interfacial phenomena; colloidal dispersion gels

Special Issue Information

Dear Colleagues,

Nuclear Magnetic Resonance (NMR) spectroscopy is a nondestructive technique that can be used to characterize a wide variety of systems. Sustained development of both methodology and instrumentation have allowed NMR to hold a special place as a powerful technology with applications in pure sciences, medicine, drug development, and important branches of industry. NMR provides precise structural information down to each atom and bond in a molecule, and it is the only method for the determination of structures of molecules in solution. NMR can lead to chemical identification and conformational analysis of natural and synthetic chemicals. It is also a powerful technique used in the investigation of polymers in chemistry, and can provide information on the motional properties of molecules and compounds. This Special Issue of the open access journal, Magnetochemistry, devoted to NMR, furnishes researches in the field with the opportunity for authors to publish their most recent discoveries using this exciting technique.

Dr. Teresa Lehmann
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Magnetochemistry is an international peer-reviewed open access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) is waived for well-prepared manuscripts submitted to this issue. Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Diffusion in porous media

  • Diffusion probes for energy-related macromolecules (surfactants, polymers, organic acids, and asphaltenes)

  • Time-domain NMR

  • NMR applied to polymer dispersion and gels

  • NMR applied to locally ordered protein networks

  • NMR applied to molecular conformation and dynamics

  • Transport imaging

  • NMR in the solid state

  • Relaxometry

  • NMR applied to paramagnetic molecules

  • Characterization of synthetic organic and inorganic molecules through NMR

  • NMR in natural products and pharmaceutical chemistry

  • Structural analysis by two-dimensional NMR

  • Multidimensional NMR in liquids

Published Papers (8 papers)

View options order results:
result details:
Displaying articles 1-8
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle Early Stages of Biomineral Formation—A Solid-State NMR Investigation of the Mandibles of Minipigs
Magnetochemistry 2017, 3(4), 39; doi:10.3390/magnetochemistry3040039 (registering DOI)
Received: 27 October 2017 / Revised: 15 November 2017 / Accepted: 17 November 2017 / Published: 22 November 2017
PDF Full-text (1547 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Solid-state nuclear magnetic resonance (NMR) spectroscopy allows for the identification of inorganic species during the biomineral formation, when crystallite particles visible in direct imaging techniques have not yet been formed. The bone blocks surrounding dental implants in minipigs were dissected after the healing
[...] Read more.
Solid-state nuclear magnetic resonance (NMR) spectroscopy allows for the identification of inorganic species during the biomineral formation, when crystallite particles visible in direct imaging techniques have not yet been formed. The bone blocks surrounding dental implants in minipigs were dissected after the healing periods of two, four, and eight weeks, and newly formed tissues formed around the implants were investigated ex vivo. Two-dimensional 31P-1H heteronuclear correlation (HETCOR) spectroscopy is based on the distance-dependent heteronuclear dipolar coupling between phosphate- and hydrogen-containing species and provides sufficient spectral resolution for the identification of different phosphate minerals. The nature of inorganic species present at different mineralization stages has been determined based on the 31P chemical shift information. After a healing time of two weeks, pre-stages of mineralization with a rather unstructured distribution of structural motives were found. After four weeks, different structures, which can be described as nanocrystals exhibiting a high surface-to-volume ratio were detected. They grew and, after eight weeks, showed chemical structures similar to those of matured bone. In addition to hydroxyapatite, amorphous calcium phosphate, and octacalcium phosphate, observed in a reference sample of mature bone, signatures of ß-tricalcium phosphate and brushite-like structures were determined at the earlier stages of bone healing. Full article
(This article belongs to the Special Issue Nuclear Magnetic Resonance Spectroscopy)
Figures

Open AccessArticle Separation of the α- and β-Anomers of Carbohydrates by Diffusion-Ordered NMR Spectroscopy
Magnetochemistry 2017, 3(4), 38; doi:10.3390/magnetochemistry3040038 (registering DOI)
Received: 31 October 2017 / Revised: 17 November 2017 / Accepted: 20 November 2017 / Published: 22 November 2017
PDF Full-text (1377 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
This article describes the successful application of the DOSY method for the separation and analysis of the α- and β-anomers of carbohydrates with different diffusion coefficients. In addition, the DOSY method was found to effectively separate two kinds of glucopyranosides with similar aglycon
[...] Read more.
This article describes the successful application of the DOSY method for the separation and analysis of the α- and β-anomers of carbohydrates with different diffusion coefficients. In addition, the DOSY method was found to effectively separate two kinds of glucopyranosides with similar aglycon structures from a mixture. Full article
(This article belongs to the Special Issue Nuclear Magnetic Resonance Spectroscopy)
Figures

Figure 1

Open AccessArticle NMR-Assisted Structure Elucidation of an Anticancer Steroid-β-Enaminone Derivative
Magnetochemistry 2017, 3(4), 37; doi:10.3390/magnetochemistry3040037
Received: 31 October 2017 / Revised: 15 November 2017 / Accepted: 17 November 2017 / Published: 21 November 2017
PDF Full-text (2397 KB) | HTML Full-text | XML Full-text
Abstract
The fortuitous modification of a quinoline-proline-piperazine side chain linked to a steroid in the presence of lithium (trimethylsilyl) acetylide has generated an unknown product that is more active than its precursor. After having characterized two β-enaminones (two-carbon homologation compounds) that were generated from
[...] Read more.
The fortuitous modification of a quinoline-proline-piperazine side chain linked to a steroid in the presence of lithium (trimethylsilyl) acetylide has generated an unknown product that is more active than its precursor. After having characterized two β-enaminones (two-carbon homologation compounds) that were generated from a simplified model side chain, we have identified the unknown product as being the β-enaminone steroid derivative 1. NMR analysis, especially two-dimensional (2D) experiments (correlation spectroscopy (COSY), NOE spectroscopy (NOESY), heteronuclear single-quantum correlation (HSQC) and heteronuclear multiple-bond correlation (HMBC)) provided crucial information that was found essential in the characterization of enaminone 1. We also proposed a mechanism to rationalize the formation of this biologically active compound. Full article
(This article belongs to the Special Issue Nuclear Magnetic Resonance Spectroscopy)
Figures

Open AccessArticle Quantification of Squalene in Olive Oil Using 13C Nuclear Magnetic Resonance Spectroscopy
Magnetochemistry 2017, 3(4), 34; doi:10.3390/magnetochemistry3040034
Received: 11 October 2017 / Revised: 26 October 2017 / Accepted: 31 October 2017 / Published: 6 November 2017
PDF Full-text (1320 KB) | HTML Full-text | XML Full-text
Abstract
In the course of our ongoing work on the chemical characterization of Corsican olive oil, we have developed and validated a method for direct quantification of squalene using 13C Nuclear Magnetic Resonance (NMR) spectroscopy without saponification, extraction, or fractionation of the investigated
[...] Read more.
In the course of our ongoing work on the chemical characterization of Corsican olive oil, we have developed and validated a method for direct quantification of squalene using 13C Nuclear Magnetic Resonance (NMR) spectroscopy without saponification, extraction, or fractionation of the investigated samples. Good accuracy, linearity, and precision of the measurements have been observed. The experimental procedure was applied to the quantification of squalene in 24 olive oil samples from Corsica. Squalene accounted for 0.35–0.83% of the whole composition. Full article
(This article belongs to the Special Issue Nuclear Magnetic Resonance Spectroscopy)
Figures

Open AccessArticle Low Field NMR Determination of pKa Values for Hydrophilic Drugs for Students in Medicinal Chemistry
Magnetochemistry 2017, 3(3), 29; doi:10.3390/magnetochemistry3030029
Received: 6 September 2017 / Revised: 15 September 2017 / Accepted: 19 September 2017 / Published: 20 September 2017
PDF Full-text (1020 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
For an interdisciplinary approach on different topics of medicinal and analytical chemistry, we applied a known experimental pKa value determination method on the field of the bench top nuclear magnetic resonance (NMR) spectrometry of some known biologically active pyridine-based drugs, i.e., pyridoxine
[...] Read more.
For an interdisciplinary approach on different topics of medicinal and analytical chemistry, we applied a known experimental pKa value determination method on the field of the bench top nuclear magnetic resonance (NMR) spectrometry of some known biologically active pyridine-based drugs, i.e., pyridoxine hydrochloride, isoniazid, and nicotine amide. The chemical shifts of the aromatic ring protons in the 1H NMR spectrum change depending on the protonation status. The data were analyzed on dependence of the chemical shifts by different pH (pD) environments and then the pKa values were calculated. The pKa values obtained were in agreement with the literature data for the compounds, searched by the students on web programs available at our university. The importance of the pKa values in protein-ligand interactions and distribution etc. of drugs was brought up to the students’ attention. In addition, by the use of a free web application for pKa values prediction, students calculated the predicted modeled pKa value. The experimental and in-silico approaches enhance the tool box for undergraduate students in medicinal chemistry. Full article
(This article belongs to the Special Issue Nuclear Magnetic Resonance Spectroscopy)
Figures

Review

Jump to: Research

Open AccessFeature PaperReview Multi-Quanta Spin-Locking Nuclear Magnetic Resonance Relaxation Measurements: An Analysis of the Long-Time Dynamical Properties of Ions and Water Molecules Confined within Dense Clay Sediments
Magnetochemistry 2017, 3(4), 35; doi:10.3390/magnetochemistry3040035
Received: 5 September 2017 / Revised: 27 October 2017 / Accepted: 31 October 2017 / Published: 14 November 2017
PDF Full-text (2384 KB) | HTML Full-text | XML Full-text
Abstract
Solid/liquid interfaces are exploited in various industrial applications because confinement strongly modifies the physico-chemical properties of bulk fluids. In that context, investigating the dynamical properties of confined fluids is crucial to identify and better understand the key factors responsible for their behavior and
[...] Read more.
Solid/liquid interfaces are exploited in various industrial applications because confinement strongly modifies the physico-chemical properties of bulk fluids. In that context, investigating the dynamical properties of confined fluids is crucial to identify and better understand the key factors responsible for their behavior and to optimize their structural and dynamical properties. For that purpose, we have developed multi-quanta spin-locking nuclear magnetic resonance relaxometry of quadrupolar nuclei in order to fill the gap between the time-scales accessible by classical procedures (like dielectric relaxation, inelastic and quasi-elastic neutron scattering) and obtain otherwise unattainable dynamical information. This work focuses on the use of quadrupolar nuclei (like 2H, 7Li and 133Cs), because quadrupolar isotopes are the most abundant NMR probes in the periodic table. Clay sediments are the confining media selected for this study because they are ubiquitous materials implied in numerous industrial applications (ionic exchange, pollutant absorption, drilling, waste storing, cracking and heterogeneous catalysis). Full article
(This article belongs to the Special Issue Nuclear Magnetic Resonance Spectroscopy)
Figures

Figure 1

Open AccessFeature PaperReview Orientational Glasses: NMR and Electric Susceptibility Studies
Magnetochemistry 2017, 3(4), 33; doi:10.3390/magnetochemistry3040033
Received: 3 October 2017 / Revised: 11 October 2017 / Accepted: 17 October 2017 / Published: 1 November 2017
PDF Full-text (958 KB) | HTML Full-text | XML Full-text
Abstract
We review the results of a wide range of nuclear magnetic resonance (NMR)measurements of the local order parameters and the molecular dynamics of solid ortho-para hydrogen mixtures and solid nitrogen-argon mixtures that form novel molecular orientational glass states at low temperatures. From the
[...] Read more.
We review the results of a wide range of nuclear magnetic resonance (NMR)measurements of the local order parameters and the molecular dynamics of solid ortho-para hydrogen mixtures and solid nitrogen-argon mixtures that form novel molecular orientational glass states at low temperatures. From the NMR measurements, the distribution of the order parameters can be deduced and, in terms of simple models, used to analyze the thermodynamic measurements of the heat capacities of these systems. In addition, studies of the dielectric susceptibilities of the nitrogen-argon mixtures are reviewed in terms of replica symmetry breaking analogous to that observed for spin glass states. It is shown that this wide set of experimental results is consistent with orientation or quadrupolar glass ordering of the orientational degrees of freedom. Full article
(This article belongs to the Special Issue Nuclear Magnetic Resonance Spectroscopy)
Figures

Figure 1

Open AccessReview Characterization of Halogen Bonded Adducts in Solution by Advanced NMR Techniques
Magnetochemistry 2017, 3(4), 30; doi:10.3390/magnetochemistry3040030
Received: 7 September 2017 / Revised: 16 September 2017 / Accepted: 20 September 2017 / Published: 25 September 2017
PDF Full-text (3161 KB) | HTML Full-text | XML Full-text
Abstract
In the last 20 years, a huge volume of experimental work into halogen bonding (XB) has been produced. Most of the systems have been characterized by solid state X-ray crystallography, whereas in solution the only routine technique is titration (by using 1H
[...] Read more.
In the last 20 years, a huge volume of experimental work into halogen bonding (XB) has been produced. Most of the systems have been characterized by solid state X-ray crystallography, whereas in solution the only routine technique is titration (by using 1H and 19F nuclear magnetic resonance (NMR), infrared (IR), ultraviolet–visible (UV–Vis) or Raman spectroscopies, depending on the nature of the system), with the aim of characterizing the strength of the XB interaction. Unfortunately, titration techniques have many intrinsic limitations and they should be coupled with other, more sophisticated techniques to provide an accurate and detailed description of the geometry and stoichiometry of the XB adduct in solution. This review will show how crucial information about XB adducts can be obtained by advanced NMR techniques, nuclear Overhauser effect-based spectroscopies (NOESY, ROESY, HOESY…) and diffusion NMR techniques (PGSE or DOSY). Full article
(This article belongs to the Special Issue Nuclear Magnetic Resonance Spectroscopy)
Figures

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: NMR Structural Glycobiology
Authors: Vitor H. Pomin
Affiliation: Program of Glycobiology, Institute of Medical Biochemistry Leopoldo de Meis and University Hospital Clementino Fraga Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21941-913, Brazil (pominvh@bioqmed.ufrj.br)
Abstract: Carbohydrates are ubiquitous components of all beings and despite the early beliefs that these biomolecules were involved solely in energy-storage and metabolism, currently it is accepted by the general community that these molecules participate in signaling and regulating activities of most cellular events and pathophysiological systems. Structurally speaking, carbohydrates or glycans are the most complex biomolecules. This happens because of the (i) numerous types of existing monosaccharides; (ii) enatiomeric, anomeric and ring configurations; (iii) glycosydic types and positions; (iv) occurrence of linear or branched chains; and (v) possible presence of lateral substituents (various types of chemical groups exist) which can be attached also in different positions of the sugar ring. Nuclear Magnetic Resonance (NMR) spectroscopy has been the most informative, useful and exploited analytical technique in structural analysis of carbohydrates. This is due to the fact that NMR enables a series of analyses on glycans such as (i) accurate structure characterization/determination; (ii) measurements of parameters regarding molecular motion (dynamics); (iii) assessment of the 3D structures (usually assisted by computational techniques of Molecular Modeling and/or Molecular Dynamics) of the composing monosaccharides (ring conformers) and the overall conformational states of the glycan chains either free in solution or bound to proteins; and (iv) analysis of the resultant intermolecular complexes with functional proteins through either the protein or the carbohydrate perspective. In this review, after a general introduction on the principal NMR parameters utilized for achieving such set of structural information, discussion moves towards some NMR-based works on representative sugars.


Title: As far as enantiomeric discrimination of 2-alkyl-5-methyl-2-pyrroline goes
Authors: Bruna Z. Costa, Maiara S. Santos, Hugo C. Loureiro, Dosil P. de Jesus, Anita J. Marsaioli, Cláudio F. Tormena
Affiliation: Chemistry Institute, University of Campinas, Campinas – SP, Brazil.
Abstract: From the analytical point of view 1H NMR spectra have all required data for fast identification and quantitation, however enantiomeric discrimination is limited to the use of chiral solvating agents (CSA). The enantiomeric excesses have to deal with the superposition of multiplets due to scalar spin-spin couplings, which can be solved by transforming them into singlets by homodecoupling during the acquisition time (pure shift methodologies). Therefore, this work aims at the enantiomeric discrimination and enantiomeric excess determination of 2-alkyl-5-methyl-2-pyrrolines with scarce literature data on their enantiomeric separation. In this work, we evaluated the enantiomeric separation of 2-hexyl-5-methyl-2-pyrroline (1, Figure 1), which was synthesized by enzymatic transamination/cyclization of 2,5-undecadione. Three 1H NMR techniques were applied to study the enantiomeric discrimination of this pyrroline promoted by (S)-binol as chiral solvating agent (CSA): regular 1H experiment, PSYCHE1 and HOBS2. Figure 1 shows the results focusing on the signals of the H-5 in structure 1. Spectrum (a) was recorded in a 600 MHz NMR equipment. However, spectra (b) and (c) were recorded in a 400 MHz equipment, where the multiplets resolution were not sufficient to integrate the signals of interest. In this case, we applied PSYCHE (b) and HOBS (c) pure shifts methodologies, which showed consistent results (enantiomeric excess about 40-42%) when compared to 1H experiment at 600 MHz (42%). These methodologies were validated by capillary electrophoresis using β-cyclodextrin sulfate as CSA, the enantiomeric excess of 42% was consistent with the NMR. Therefore, these results attested that 2-alkyl-5-methyl-2-pyrrolines could be enantiomerically discriminated by using CSA, such as (S)-binol and β-cyclodextrin sulfate, and that this discrimination was successfully evaluated by 1H NMR techniques and capillary electrophoresis.

 

Title: Characterization of Halogen Bonded Adducts in Solution by Advanced NMR Techniques
Type of Paper: Review
Authors: Gianluca Ciancaleoni
Affiliation: Dipartimento di Chimica e Chimica Industriale (DCCI), Università di Pisa, Via Giuseppe Moruzzi, 13 - 56124 Pisa, Italy
Abstract: In the last 20 years a huge amount of experimental results about halogen bonding (XB) has been produced. Most of the systems have been characterized by solid state X-ray crystallography and, often, the resulting structure is just assumed to be the same in solution and in solid state. For this reason, only titration techniques (by using 1H and 19F NMR, IR, UV-Vis or Raman spectroscopies, depending on the nature of the system) are routinely employed in solution studies, with the aim to characterize the strength of the XB interaction. Unfortunately, titrations have many limitations and they should be coupled with other, more sophisticated techniques to have an accurate and detailed description of the geometry and stoichiometry of the XB adduct in solution. In this review, it will be shown how crucial information about XB adducts can be obtained by advanced NMR techniques, as the Nuclear Overhauser Effect Spectroscopies (NOESY, ROESY, HOESY…) and diffusion NMR techniques (PGSE or DOSY).

 

Title: Nuclear Magnetic Resonance, a powerful tool in cultural heritag
Authors:
Donatella Capitani, Valeria Di Tullio, Noemi Proietti
Affiliation: Istituto di Metodologie Chimiche, CNR Area della Ricerca di Roma 1, Via Salaria km 29,300, 00015 Monterotondo (Rome), Italy
Abstract: The knowledge of materials and causes  of degradation, the development of new methods and materials aimed at lengthening the life time of artifacts, are mandatory in the correct safeguard of cultural heritage. Laboratory NMR instrumentation allows the characterization  of  organic, inorganic and hybrid materials in the liquid, solid, and semi-solid  state. The availability  of portable NMR instrumentation allows the study  of  large objects such as frescoes,  monuments, and in general any buildings fully preserving the integrity and the dimension of the object under investigation.  Parameters measured by NMR are important to establish the state of degradation of  objects, to evaluate  performances of consolidative, protective, and cleaning treatments  carried out on porous materials, to monitor the detachment of the painted layer from the plaster, to quantitatively map the dampness in wall paintings. Portable NMR devices are nowadays available for obtaining NMR stratigraphy with microscopic spatial resolution and investigating the layer structure of artifacts. Cases of application  of NMR techniques in the field of cultural heritage will be shown to illustrate the potentialities of NMR  in this field of research.
[1] Bernard  Blümich, Juan Perlo,  Federico Casanova,. Progr. Nucl. Magn. Reson. Spectrosc.  200852, 197-269.
[2] Donatella Capitani, Valeria  Di Tullio, Noemi Proietti,  Progr. Nucl. Magn. Reson. Spectrosc. 2012, 64, 29-69.
[3] Jonathan  Mitchell, Peter Blümer, Peter  McDonald, Progr. Nucl. Magn. Reson 2006, 48, 161-181.
[4] Perlo, J., Casanova, F., Blümich, B. (2005): J. Magn. Reson., 176, 64-70.

 

Title: NMR-based metabolomics identifies depth-dependent variation in the biochemical composition of agricultural soils subjected to anaerobic soil disinfestation
Corresponding author: Natosha L. Finley
Affiliation: Department of Microbiology, Miami University, 700 East High Street, 32 Pearson Hall, Oxford, Oh, 45056, USA; Tel: (513) 529-7994; Fax: (708) 216-6308; Email: finleynl@miamioh.edu
Abstract: Anaerobic soil disinfestation (ASD) treatment, which is known to be an alternative to chemical pest and pathogen control, modulates the water content, microbial community composition, and biochemical profile of agricultural fields. In this study, we utilize NMR-based metabolomics and principle component analysis (PCA) to examine depth-dependent changes in biochemical profiles of soils following ASD-treatment. The chemical identities of aqueous compounds extracted from soils were determined using one (1D) and two-dimensional (2D) NMR spectroscopy. We found that organic acids, among other metabolites, were present in both shallow (0-15 cm) and deep (16-30 cm) soils following ASD treatment. PCA revealed that high levels of organic acids dominated the metabolic profiles of both soil depths, which masked the importance of other metabolites in the biochemical composition of ASD-treated soils. Using a multistep PCA approach, we removed the contribution of organic acids to highlight the influence of minor metabolites in distinguishing between ASD treatments.  The separation in metabolic profiles between ASD treatment groups was due in part to the presence of compounds associated with osmoregulation in cells, which were only detected in shallow soils. In summary, our findings reveal the utility of NMR-based metabolomics in studying the potential link between irrigation, soil depth, and metabolite composition in ASD–treated soils.

Type of paper: Article
Title: Calcium‐Dependent Interaction Occurs Between Slow Skeletal Myosin Binding Protein C and Calmodulin
Authors: Tzvia I. Springer 1,†, Christian W. Johns 2, Jana Cable 1, Brian Leei Lin 3, Sakthivel Sadayappan 4 and Natosha L. Finley 2,*
Affiliations: 1 Department of Microbiology, Miami University, Oxford, OH, United States of America; cablejm@miamioh.edu;
2 Cell, Molecular, and Structural Biology Program, Miami University, Oxford, OH 45056, United States of America; johnscw@miamioh.edu
3 Department of Cardiology, Johns Hopkins University, Baltimore, Maryland 21205, United States of America; blin29@jhmi.edu
4 Department of Internal Medicine, Heart Branch of the Heart, Lung and Vascular Institute, University of Cincinnati College of Medicine, Cincinnati, OH 45267, United States of America; SADAYASL@ucmail.uc.edu
† Present affiliation Department of Biophysics, Medical College of Wisconsin, 8701 W. Watertown Plank Road, Milwaukee, Wisconsin, 2042, USA; tspringer@mcw.edu
* Correspondence: finleynl@miamioh.edu; Tel.: +01‐513‐529‐0950
Abstract: Myosin binding protein C (MyBP‐C) is a multi‐domain protein that participates in
regulation of muscle contraction through dynamic interactions with actin and myosin. Three
primary isoforms of MyBP‐C exist: cardiac (cMyBP‐C), fast skeletal (fsMyBP‐C), and slow skeletal (ssMyBP‐C). The N‐terminal region of cMyBP‐C contains the M‐motif, a three‐helix bundle that binds Ca2+‐loaded calmodulin (CaM), but less is known about N‐terminal ssMyBP‐C and fsMyBP‐C. Here, we characterized the conformation of a recombinant N‐terminal fragment of
ssMyBP‐C (ssC1C2) using differential scanning fluorimetry, nuclear magnetic resonance, and
molecular modeling. Our studies revealed that ssC1C2 has altered thermal stability in the presence and absence of CaM. We observed that site‐specific interaction between CaM and the M‐motif of ssC1C2 occurs in a Ca2+‐dependent manner. Molecular modeling supported that the M‐motif of ssC1C2 likely adopts a three‐helix bundle fold comparable to cMyBP‐C. Our study provides evidence of that ssMyBP‐C has overlapping structural determinants in common with the cardiac isoform that are important in controlling protein‐protein association. We shed light on the differential molecular regulation of contractility that exists between skeletal and cardiac muscles.
Keywords: calcium; calmodulin; molecular model; MyBP‐C; NMR; protein

 

Back to Top