Voltammetry and molecular assembly of G-quadruplex DNAzyme on single-crystal Au(111)-electrode surfaces – hemin as an electrochemical intercalator

Zhang, Ling; Ulstrup, Jens; Zhang, Jingdong

doi:10.1039/c6fd00091f

Cited by 7 publications

(15 citation statements)

References 52 publications

(167 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…compared with natural biological environments. Such questions can be approached differently, by electrochemical STM (or cAFM) and have been addressed recently 64 . In situ STM to molecular resolution of the 5'GGG A GGGT GGGA GGG 3 G4-quadruplex DNAzyme in biological buffer under electrochemical control was achieved, cf.…”

Section: Single-molecule G-quadruplex Conductivity -Stm Cafm and In mentioning

confidence: 99%

See 1 more Smart Citation

Electrochemical single-molecule conductivity of duplex and quadruplex DNA

Zhang

Ulstrup

2017

Current Opinion in Electrochemistry

Self Cite

View full text Add to dashboard Cite

 Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

show abstract

Section: Single-molecule G-quadruplex Conductivity -Stm Cafm and In mentioning

confidence: 99%

“…(E and F) CVs of 12Gquadruplex based DNAzyme and free heme (E) and of FePPIX free 12G-quadruplex (F) on Au(111)electrode in 5 mM sodium acetate, pH 7.2. From Ref 64. with permission.…”

mentioning

confidence: 99%

Electrochemical single-molecule conductivity of duplex and quadruplex DNA

Zhang

Ulstrup

2017

Current Opinion in Electrochemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…Previous work suggests that the heme porphyrin ring intercalates into G-quadruplex (G4) DNA structures, affecting their stability and function (Poon et al, 2011;Saito et al, 2012aSaito et al, , 2012bSen and Poon, 2011;Shibata et al, 2016;Yamamoto et al, 2015). G4s are DNA and RNA non-canonical structures held together by guanine base quartets and stabilized by specific cations (Kosman and Juskowiak, 2016;Shumayrikh et al, 2015;Zhang et al, 2016). Moreover, G4 DNA can sequester labile heme to form DNA:heme complexes, which act as DNAzymes, exhibiting robust peroxidase and peroxygenase activities (Sen and Poon, 2011;Travascio et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

Scavenging of Labile Heme by Hemopexin Is a Key Checkpoint in Cancer Growth and Metastases

Canesin

Ruscio

et al. 2020

Cell Reports

View full text Add to dashboard Cite

SUMMARY Hemopexin (Hx) is a scavenger of labile heme. Herein, we present data defining the role of tumor stroma-expressed Hx in suppressing cancer progression. Labile heme and Hx levels are inversely correlated in the plasma of patients with prostate cancer (PCa). Further, low expression of Hx in PCa biopsies characterizes poorly differentiated tumors and correlates with earlier time to relapse. Significantly, heme promotes tumor growth and metastases in an orthotopic murine model of PCa, with the most aggressive phenotype detected in mice lacking Hx. Mechanistically, labile heme accumulates in the nucleus and modulates specific gene expression via interacting with guanine quadruplex (G4) DNA structures to promote PCa growth. We identify c-MYC as a heme:G4-regulated gene and a major player in heme-driven cancer progression. Collectively, these results reveal that sequestration of labile heme by Hx may block heme-driven tumor growth and metastases, suggesting a potential strategy to prevent and/or arrest cancer dissemination.

show abstract

“…Metalloporphyrins are the active sites of a broad range of hemoproteins including cytochromes, hemoglobin and myoglobin, and enzymes, involved in electron transfer (ET), oxygen storage and transport, and biochemical catalysis. − Modifications of porphyrin axial ligands and side groups also enable mapping the catalysis of a variety of oxidative processes of hydrocarbons and sulfides. − The unique electronic properties of the metalloporphyrins, rooted in subtle ligand field control between low- (LS) and high-spin (HS) states, have inspired development of artificial enzymes as well as electrocatalysts via π–π electron conjugation or intercalation. ,, Surface assembly of metalloporphyrins has further been reported extensively using electrochemistry and electrochemical scanning tunneling microscopy ( in situ STM) on single–crystal gold, copper, and highly oriented pyrolytic graphite (HOPG) surfaces. − …”

Section: Introductionmentioning

confidence: 99%

“…We have recently reported voltammetry/ in situ STM of the heme group stacked onto a 12-guanine DNA quadruplex (DNAzyme) immobilized on Au(111) via a thiol linker . The voltammetry was unusual, first with high conductivity through the quadruplex and second with two rather than a single voltammetric signal as otherwise broadly known.…”

Section: Introductionmentioning

confidence: 99%

Redox Potentials and Electronic States of Iron Porphyrin IX Adsorbed on Single Crystal Gold Electrode Surfaces

et al. 2018

Self Cite

View full text Add to dashboard Cite

Metalloporphyrins are active sites in metalloproteins and synthetic catalysts. They have also been studied extensively by electrochemistry as well as being prominent targets in electrochemical scanning tunneling microscopy (STM). Previous studies of FePPIX adsorbed on graphite and alkylthiol modified Au electrodes showed a pair of reversible Fe(III/II)PPIX peaks at about -0.41 V (vs NHE) at high solution pH. We recently used iron protoporphyrin IX (FePPIX) as an intercalating probe for long-range electrochemical electron transfer through a G-quadruplex oligonucleotide (DNAzyme); this study disclosed two, rather than a single pair of voltammetric peaks with a new and dominating peak, shifted 200 mV positive relative to the ≈-0.4 V peak. Prompted by this unexpected observation, we report here a study of the voltammetry of FePPIX itself on single-crystal Au(111), (100), and (110) and polycrystalline Au electrode surfaces. In all cases the dominating pair of new Fe(III/II)PPIX redox peaks, shifted positively by more than 200 mV compared to those of previous studies appeared. This observation is supported by density functional theory (DFT) which shows that strong dispersion forces in the FePPIX/Au electronic interaction drive the midpoint potential toward positive values. The FePPIX spin states depend on interaction with the Au(111) interface, converting all the Fe(II)/(III)PPIX species into low-spin states. These results support electrochemical evidence for the nature of the electronic coupling between FePPIX and Au-surfaces, and the electronic states of adsorbate molecules, with a bearing also on recent reports of magnetic FePPIX/Au(111) interactions in ultrahigh vacuum (UHV).

show abstract

Voltammetry and molecular assembly of G-quadruplex DNAzyme on single-crystal Au(111)-electrode surfaces – hemin as an electrochemical intercalator

Abstract: . This is supported by in situ STM which discloses single-molecule G-quartet structures with a size of 1.6 ± 0.2 nm.

Cited by 7 publications

References 52 publications

Electrochemical single-molecule conductivity of duplex and quadruplex DNA

Electrochemical single-molecule conductivity of duplex and quadruplex DNA

Scavenging of Labile Heme by Hemopexin Is a Key Checkpoint in Cancer Growth and Metastases

Redox Potentials and Electronic States of Iron Porphyrin IX Adsorbed on Single Crystal Gold Electrode Surfaces

Contact Info

Product

Resources

About