scholarly journals Recognition and discrimination of DNA quadruplexes by acridine-peptide conjugates

2009 ◽  
Vol 7 (1) ◽  
pp. 76-84 ◽  
Author(s):  
James E. Redman ◽  
J. M. Granadino-Roldán ◽  
James A. Schouten ◽  
Sylvain Ladame ◽  
Anthony P. Reszka ◽  
...  
Keyword(s):  
Peptide Conjugates ◽  
Dna Quadruplexes

68Ga-labeled HBED-CC Variant of uPAR Targeting Peptide AE105 Compared with 68Ga-NODAGA-AE105

2019 ◽  
Vol 18 (9) ◽  
pp. 1289-1294 ◽  
Author(s):  
Kusum Vats ◽  
Rohit Sharma ◽  
Haladhar D. Sarma ◽  
Drishty Satpati ◽  
Ashutosh Dash
Keyword(s):  
Solid Phase ◽  
Evaluation Studies ◽  
Radiochemical Yield ◽  
In Vivo Evaluation ◽  
Peptide Conjugates ◽  
Biodistribution Studies ◽  
Target Organs ◽  
U87mg Tumor

Aims: The urokinase Plasminogen Activator Receptors (uPAR) over-expressed on tumor cells and their invasive microenvironment are clinically significant molecular targets for cancer research. uPARexpressing cancerous lesions can be suitably identified and their progression can be monitored with radiolabeled uPAR targeted imaging probes. Hence this study aimed at preparing and evaluating two 68Ga-labeled AE105 peptide conjugates, 68Ga-NODAGA-AE105 and 68Ga-HBED-CC-AE105 as uPAR PET-probes. Method: The peptide conjugates, HBED-CC-AE105-NH2 and NODAGA-AE105-NH2 were manually synthesized by standard Fmoc solid phase strategy and subsequently radiolabeled with 68Ga eluted from a commercial 68Ge/68Ga generator. In vitro cell studies for the two radiotracers were performed with uPAR positive U87MG cells. Biodistribution studies were carried out in mouse xenografts with the subcutaneously induced U87MG tumor. Results: The two radiotracers, 68Ga-NODAGA-AE105 and 68Ga-HBED-CC-AE105 that were prepared in >95% radiochemical yield and >96% radiochemical purity, exhibited excellent in vitro stability. In vivo evaluation studies revealed higher uptake of 68Ga-HBED-CC-AE105 in U87MG tumor as compared to 68Ga-NODAGAAE105; however, increased lipophilicity of 68Ga-HBED-CC-AE105 resulted in slower clearance from blood and other non-target organs. The uPAR specificity of the two radiotracers was ascertained by significant (p<0.05) reduction in the tumor uptake with a co-injected blocking dose of unlabeled AE-105 peptide. Conclusion: Amongst the two radiotracers studied, the neutral 68Ga-NODAGA-AE105 with more hydrophilic chelator exhibited faster clearance from non-target organs. The conjugation of HBED-CC chelator (less hydrophilic) resulted in negatively charged 68Ga-HBED-CC-AE105 which was observed to have high retention in blood that decreased target to non-target ratios.

Peptide conjugates of lactoferricin analogues and antimicrobials—Design, chemical synthesis, and evaluation of antimicrobial activity and mammalian cytotoxicity

Peptides ◽  
2019 ◽  
Vol 117 ◽  
pp. 170079 ◽  
Author(s):  
Natalia Ptaszyńska ◽  
Katarzyna Olkiewicz ◽  
Joanna Okońska ◽  
Katarzyna Gucwa ◽  
Anna Łęgowska ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Synthesis ◽  
Peptide Conjugates

scholarly journals Binding and Partial Denaturing of G-quartet DNA by Cdc13p ofSaccharomyces cerevisiae

2001 ◽  
Vol 276 (50) ◽  
pp. 47671-47674 ◽  
Author(s):  
Yi-Chien Lin ◽  
Jing-Wen Shih ◽  
Chia-Ling Hsu ◽  
Jing-Jer Lin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Intermolecular Association ◽  
Telomere Association ◽  
Dna Quadruplex ◽  
Telomere Replication ◽  
Dna Quadruplexes

The protein Cdc13p binds telomeresin vivoand is essential for the maintenance of the telomeres ofSaccharomyces cerevisiae. In addition, Cdc13p is known to bind single-stranded TG1–3DNAin vitro. Here we have shown that Cdc13p also binds DNA quadruplex, G-quartet, formed by TG1–3DNA. Moreover, the binding of Cdc13p causes a partial denaturing of the G-quartet DNA. Formation of DNA quadruplexes may involve the intermolecular association of TG1–3DNA and inhibit the extension of telomeres by telomerase. Thus, our finding suggests that Cdc13p may disrupt telomere association and facilitate telomere replication.

Synthesis of Nucleic Acid-Peptide Conjugates Targeted to Proteins

2011 ◽  
Vol 51 (8-9) ◽  
pp. 876-884 ◽  
Author(s):  
Anne Erben ◽  
Oliver Seitz
Keyword(s):  
Nucleic Acid ◽  
Peptide Conjugates

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

2016 ◽  
Vol 193 ◽  
pp. 99-112 ◽  
Author(s):  
Ling Zhang ◽  
Jens Ulstrup ◽  
Jingdong Zhang
Keyword(s):  
Single Crystal ◽  
Single Molecule ◽  
Electrode Surface ◽  
Molecular Assembly ◽  
Electrode Surfaces ◽  
Potential Control ◽  
G Quadruplex ◽  
Tunnelling Microscopy ◽  
Dna Quadruplexes

DNA quadruplexes (qs) are a class of “non-canonical” oligonucleotides (OGNs) composed of stacked guanine (G) quartets stabilized by specific cations. Metal porphyrins selectively bind to G-qs complexes to form what is known as DNAzyme, which can exhibit peroxidase and other catalytic activity similar to heme group metalloenzymes. In the present study we investigate the electrochemical properties and the structure of DNAzyme monolayers on single-crystal Au(111)-electrode surfaces using cyclic voltammetry and scanning tunnelling microscopy under electrochemical potential control (in situ STM). The target DNAzyme is formed from a single-strand OGN with 12 guanines and iron(iii) porphyrin IX (hemin), and assembles on Au(111) through a mercapto alkyl linker. The DNAzyme monolayers exhibit a strong pair of redox peaks at 0.0 V (NHE) at pH 7 in acetate buffer, shifted positively by about 50 mV compared to free hemin weakly physisorbed on the Au(111)-electrode surface. The voltammetric hemin signal of DNAzyme is enhanced 15 times compared with that of hemin adsorbed directly on the Au(111)-electrode surface. This is indicative of both the formation of a close to dense DNAzyme monolayer and that hemin is strongly bound to the immobilized 12G-qs in well-defined orientation favorable for interfacial ET with a rate constant of 6.0 ± 0.4 s−1. This is supported by in situ STM which discloses single-molecule G-quartet structures with a size of 1.6 ± 0.2 nm.

High-Efficiency Intracellular Magnetic Labeling with Novel Superparamagnetic-Tat Peptide Conjugates

1999 ◽  
Vol 10 (2) ◽  
pp. 186-191 ◽  
Author(s):  
Lee Josephson ◽  
Ching-Hsuan Tung ◽  
Anna Moore ◽  
Ralph Weissleder
Keyword(s):  
High Efficiency ◽  
Tat Peptide ◽  
Peptide Conjugates ◽  
Magnetic Labeling

Enhanced Strand Invasion by Peptide Nucleic Acid−Peptide Conjugates†

Biochemistry ◽  
2002 ◽  
Vol 41 (37) ◽  
pp. 11118-11125 ◽  
Author(s):  
Kunihiro Kaihatsu ◽  
Dwaine A. Braasch ◽  
Ahmet Cansizoglu ◽  
David R. Corey
Keyword(s):  
Nucleic Acid ◽  
Peptide Nucleic Acid ◽  
Peptide Conjugates ◽  
Strand Invasion
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