Improving Spin Probe Methodologies to Investigate Supramolecular Assemblies

Lucarini, Marco

doi:10.1002/ejoc.201901871

Cited by 9 publications

(3 citation statements)

References 81 publications

(60 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…26,27 Among the CB-n (n = 6 -8) family, CB-7 is the most water soluble host and has the strongest association constants, Ka = 7.2 × 10 17 M -1 in D2O, with selected diamagnetic dicationic guests. [28][29][30][31] However, nitroxides as guests are far behind, [32][33][34] with the reports of strongest Ka  2 × 10 5 M -1 for dicationic nitroxide radical bPTO (Figure 1) 35 and Ka = 2.8 × 10 6 M −1 for a TEMPO-cobaltocenium derivative, based on inclusion of cobaltocenium moiety within CB-7. 36 Nevertheless, the typical association constants for neutral adamantane derivatives with CB-7 are several orders magnitude higher than those with β-CD, 26,37 thus much tighter complexes with superb association constant may be expected for the DZD nitroxide and CB-7 than for β-CD.…”

Section: Introductionmentioning

confidence: 93%

Cucurbit[7]uril Enhances Distance Measurements of Spin-Labeled Proteins

Yang,

Stein,

Pink

et al. 2023

Preprint

View full text Add to dashboard Cite

We report complex formation between the chloroacetamide 2,6-diazaadamantane nitroxide radical (ClA-DZD) and cucurbit[7]uril (CB-7), for which the association constant in water, Ka = 1.9 * 106 M-1, is at least one order of magnitude higher than the previously studied organic radicals. The radical is highly immobilized by CB-7, as indicated by the increase of the rotational correlation time, τrot, by a factor of 36, relative to that in the buffer solution. The X-ray structure of ClA-DZD@CB-7 shows the encapsulated DZD guest inside the undistorted CB-7 host, with the pendant group protruding outside. Upon addition of CB-7 to T4 Lysozyme (T4L) doubly spin-labeled with the iodoacetamide derivative of DZD, we observe the increase in τrot and electron spin coherence time, Tm, along with the narrowing of inter-spin distance distributions. Sensitivity of the DEER measurements at 83 K increases by a factor 4-9, compared to the common spin label such as MTSL, which is not affected by CB-7. Inter-spin distances of 3-nm could be reliably measured in water/glycerol up to temperatures near the glass transition/melting temperature of the matrix at 200 K, thus bringing us closer to the goal of supramolecular recogni-tion-enabled long-distance DEER measurements at near physiological temperatures. The X-ray structure of DZD-T4L 65 at 1.12 angstrom resolution allows for unambiguous modeling of the DZD label (0.88 occupancy), indicating undisturbed structure and confirmation of the protein.

show abstract

Section: Introductionmentioning

confidence: 93%

Cucurbit[7]uril Enhances Distance Measurements of Spin-Labeled Proteins

Yang,

Stein,

Pink

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Cucurbit[n]urils (CB-n) is a family of macrocyclic cages with exceptional recognition properties in aqueous medium that have been widely investigated for its applications in drug delivery system and advanced functional materials. , Among the CB-n ( n = 6–8) family, CB-7 is the most water-soluble host and has the strongest association constants, K a = 7.2 × 10 17 M –1 in D 2 O, with selected diamagnetic dicationic guests. − However, nitroxides as guests are far behind, − with the reports of strongest K a ≈ 2 × 10 5 M –1 for dicationic nitroxide radical bPTO (Figure ) and K a = 2.8 × 10 6 M –1 for a TEMPO-cobaltocenium derivative, based on inclusion of cobaltocenium moiety within CB-7 . Nevertheless, the typical association constants for neutral adamantane derivatives with CB-7 are several orders magnitude higher than those with β-CD, , thus much tighter complexes with superb association constant may be expected for the DZD nitroxide and CB-7 than for β-CD.…”

Section: Introductionmentioning

confidence: 99%

Cucurbit[7]uril Enhances Distance Measurements of Spin-Labeled Proteins

Yang,

Stein,

Pink

et al. 2023

J. Am. Chem. Soc.

View full text Add to dashboard Cite

We report complex formation between the chloroacetamide 2,6-diazaadamantane nitroxide radical (ClA-DZD) and cucurbit[7]uril (CB-7), for which the association constant in water, K a = 1.9 × 106 M–1, is at least 1 order of magnitude higher than the previously studied organic radicals. The radical is highly immobilized by CB-7, as indicated by the increase in the rotational correlation time, τrot, by a factor of 36, relative to that in the buffer solution. The X-ray structure of ClA-DZD@CB-7 shows the encapsulated DZD guest inside the undistorted CB-7 host, with the pendant group protruding outside. Upon addition of CB-7 to T4 Lysozyme (T4L) doubly spin-labeled with the iodoacetamide derivative of DZD, we observe the increase in τrot and electron spin coherence time, T m, along with the narrowing of interspin distance distributions. Sensitivity of the DEER measurements at 83 K increases by a factor 4–9, compared to the common spin label such as MTSL, which is not affected by CB-7. Interspin distances of 3 nm could be reliably measured in water/glycerol up to temperatures near the glass transition/melting temperature of the matrix at 200 K, thus bringing us closer to the goal of supramolecular recognition-enabled long-distance DEER measurements at near physiological temperatures. The X-ray structure of DZD-T4L 65 at 1.12 Å resolution allows for unambiguous modeling of the DZD label (0.88 occupancy), indicating an undisturbed structure and conformation of the protein.

show abstract

“…(g) as participants in host–guest interactions in supramolecular chemistry for the creation of nanomachines and polyradical ensembles [ 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 ];…”

Section: Introductionmentioning

confidence: 99%

Spirocyclic Nitroxides as Versatile Tools in Modern Natural Sciences: From Synthesis to Applications. Part I. Old and New Synthetic Approaches to Spirocyclic Nitroxyl Radicals

Zaytseva

Mazhukin

2021

Molecules

View full text Add to dashboard Cite

Spirocyclic nitroxyl radicals (SNRs) are stable paramagnetics bearing spiro-junction at α-, β-, or γ-carbon atom of the nitroxide fragment, which is part of the heterocyclic system. Despite the fact that the first representatives of SNRs were obtained about 50 years ago, the methodology of their synthesis and their usage in chemistry and biochemical applications have begun to develop rapidly only in the last two decades. Due to the presence of spiro-function in the SNRs molecules, the latter have increased stability to various reducing agents (including biogenic ones), while the structures of the biradicals (SNBRs) comprises a rigid spiro-fused core that fixes mutual position and orientation of nitroxide moieties that favors their use in dynamic nuclear polarization (DNP) experiments. This first review on SNRs will give a glance at various strategies for the synthesis of spiro-substituted, mono-, and bis-nitroxides on the base of six-membered (piperidine, 1,2,3,4-tetrahydroquinoline, 9,9′(10H,10H′)-spirobiacridine, piperazine, and morpholine) or five-membered (2,5-dihydro-1H-pyrrole, pyrrolidine, 2,5-dihydro-1H-imidazole, 4,5-dihydro-1H-imidazole, imidazolidine, and oxazolidine) heterocyclic cores.

show abstract

Improving Spin Probe Methodologies to Investigate Supramolecular Assemblies

Cited by 9 publications

References 81 publications

Cucurbit[7]uril Enhances Distance Measurements of Spin-Labeled Proteins

Cucurbit[7]uril Enhances Distance Measurements of Spin-Labeled Proteins

Cucurbit[7]uril Enhances Distance Measurements of Spin-Labeled Proteins

Spirocyclic Nitroxides as Versatile Tools in Modern Natural Sciences: From Synthesis to Applications. Part I. Old and New Synthetic Approaches to Spirocyclic Nitroxyl Radicals

Contact Info

Product

Resources

About