Fluorescence-detected circular dichroism of ethidium in vivo and bound to deoxyribonucleic acid in vitro

Biochemistry ◽  
1985 ◽  
Vol 24 (12) ◽  
pp. 2819-2822 ◽  
Author(s):  
Michael L. Lamos ◽  
Douglas H. Turner
Keyword(s):  
Circular Dichroism ◽  
Deoxyribonucleic Acid ◽  
Circular Dichroïsm

scholarly journals Peptides of pHLIP family for targeted intracellular and extracellular delivery of cargo molecules to tumors

2018 ◽  
Vol 115 (12) ◽  
pp. E2811-E2818 ◽  
Author(s):  
Linden C. Wyatt ◽  
Anna Moshnikova ◽  
Troy Crawford ◽  
Donald M. Engelman ◽  
Oleg A. Andreev ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Targeted Delivery ◽  
Tumor Imaging ◽  
Intracellular Delivery ◽  
Membrane Lipid ◽  
Wide Range ◽  
Ph Dependent ◽  
Circular Dichroïsm

The pH (low) insertion peptides (pHLIPs) target acidity at the surfaces of cancer cells and show utility in a wide range of applications, including tumor imaging and intracellular delivery of therapeutic agents. Here we report pHLIP constructs that significantly improve the targeted delivery of agents into tumor cells. The investigated constructs include pHLIP bundles (conjugates consisting of two or four pHLIP peptides linked by polyethylene glycol) and Var3 pHLIPs containing either the nonstandard amino acid, γ-carboxyglutamic acid, or a glycine−leucine−leucine motif. The performance of the constructs in vitro and in vivo was compared with previous pHLIP variants. A wide range of experiments was performed on nine constructs including (i) biophysical measurements using steady-state and kinetic fluorescence, circular dichroism, and oriented circular dichroism to study the pH-dependent insertion of pHLIP variants across the membrane lipid bilayer; (ii) cell viability assays to gauge the pH-dependent potency of peptide-toxin constructs by assessing the intracellular delivery of the polar, cell-impermeable cargo molecule amanitin at physiological and low pH (pH 7.4 and 6.0, respectively); and (iii) tumor targeting and biodistribution measurements using fluorophore-peptide conjugates in a breast cancer mouse model. The main principles of the design of pHLIP variants for a range of medical applications are discussed.

A Circular Dichroism and Photoacoustic Dual-Mode Probe for Detection In Vitro and Imaging In Vivo of Hydroxyl Radicals

2022 ◽  
Author(s):  
Shulong Wang ◽  
Liangliang Zhang ◽  
Yanni Luo ◽  
Yulong Bai ◽  
Yong Huang ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Hydroxyl Radicals ◽  
Dual Mode ◽  
Circular Dichroïsm

Phytochemical and Bioactive Potential of in vivo and in vitro Grown Plants of Centaurea ragusina L. - Detection of DNA/RNA Active Compounds in Plant Extracts via Thermal Denaturation and Circular Dichroism

2017 ◽  
Vol 28 (6) ◽  
pp. 584-592 ◽  
Author(s):  
Valerija Vujčić ◽  
Sandra Radić Brkanac ◽  
Ivana Radojčić Redovniković ◽  
Siniša Ivanković ◽  
Ranko Stojković ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Plant Extracts ◽  
Thermal Denaturation ◽  
Active Compounds ◽  
Bioactive Potential ◽  
Circular Dichroïsm

scholarly journals Electronic Circular Dichroism of the Cas9 Protein and gRNA:Cas9 Ribonucleoprotein Complex

2021 ◽  
Vol 22 (6) ◽  
pp. 2937
Author(s):  
Monika Halat ◽  
Magdalena Klimek-Chodacka ◽  
Jagoda Orleanska ◽  
Malgorzata Baranska ◽  
Rafal Baranski
Keyword(s):  
Circular Dichroism ◽  
Conformational Changes ◽  
Structural Changes ◽  
Electronic Circular Dichroism ◽  
Guide Rna ◽  
Cas9 Protein ◽  
Rnp Complex ◽  
Characteristic Features ◽  
Circular Dichroïsm

The Streptococcus pyogenes Cas9 protein (SpCas9), a component of CRISPR-based immune system in microbes, has become commonly utilized for genome editing. This nuclease forms a ribonucleoprotein (RNP) complex with guide RNA (gRNA) which induces Cas9 structural changes and triggers its cleavage activity. Here, electronic circular dichroism (ECD) spectroscopy was used to confirm the RNP formation and to determine its individual components. The ECD spectra had characteristic features differentiating Cas9 and gRNA, the former showed a negative/positive profile with maxima located at 221, 209 and 196 nm, while the latter revealed positive/negative/positive/negative pattern with bands observed at 266, 242, 222 and 209 nm, respectively. For the first time, the experimental ECD spectrum of the gRNA:Cas9 RNP complex is presented. It exhibits a bisignate positive/negative ECD couplet with maxima at 273 and 235 nm, and it differs significantly from individual spectrum of each RNP components. Additionally, the Cas9 protein and RNP complex retained biological activity after ECD measurements and they were able to bind and cleave DNA in vitro. Hence, we conclude that ECD spectroscopy can be considered as a quick and non-destructive method of monitoring conformational changes of the Cas9 protein as a result of Cas9 and gRNA interaction, and identification of the gRNA:Cas9 RNP complex.

Complexes of deoxyribonucleic acid with fragments of lysine-rich histone (f-1). Circular dichroism studies

Biochemistry ◽  
1971 ◽  
Vol 10 (20) ◽  
pp. 3795-3801 ◽  
Author(s):  
Gerald D. Fasman ◽  
Manuel S. Valenzuela ◽  
Alice J. Adler
Keyword(s):  
Circular Dichroism ◽  
Deoxyribonucleic Acid ◽  
Circular Dichroïsm
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