scholarly journals ComparativeIn VitroBinding Studies of TiCl2(dpme)2, Ti(ada)2(bzac)2, and TiCl2(bzac)(bpme) Titanium Complexes with Calf-Thymus DNA

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Pamita Awasthi ◽  
Nitesh Kumar ◽  
Raj Kaushal ◽  
Mohan Kumar ◽  
Shrikant Kukreti
Keyword(s):  
Circular Dichroism ◽  
Binding Constants ◽  
Blue Shift ◽  
Binding Mode ◽  
Visible Absorption ◽  
Calf Thymus ◽  
Absorption Studies ◽  
Uv Visible ◽  
Ct Dna ◽  
Circular Dichroïsm

The binding of TiCl2(dpme)2(1), (dpme = 6,6′-dimethyl-2,2′-bipyridine), Ti(ada)2(bzac)2(2), (ada = adamantylamine; bzac = benzoylacetone), and TiCl2(bzac)(bpme) (3), (bpme = 4,4′-dimethyl-2,2′-bipyrdine) with calf thymus (ct) DNA has been studied by UV-visible spectroscopy, thermal denaturation, and circular dichroism spectroscopy. In UV-visible study complexes1,2, and3showed red, blue, and red shifts, respectively, upon the addition of ct-DNA along with a significant hyperchromism. The intrinsic binding constants (Kb) calculated from UV-visible absorption studies were 2.3 × 103 M−1, 3.3 × 103 M−1and, 7.1 × 103 M−1for complexes1,2, and3, respectively. The change in melting temperature (ΔTm) was calculated to be 2-3°C for each complex. Circular dichroism (CD) study showed blue shift for complex2and red shift for complexes1and3along with rise in molecular ellipticity upon the addition of complexes. Results suggest a binding mode of complex2different than1and3.

Resonance Raman Study of the Binding of the Anticancer Drug Amsacrine to DNA

1994 ◽  
Vol 48 (7) ◽  
pp. 822-826 ◽  
Author(s):  
Catherine A. Butler ◽  
Ralph P. Cooney ◽  
William A. Denny
Keyword(s):  
Raman Spectroscopy ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Binding Mode ◽  
Resonance Raman Spectrum ◽  
Normal Coordinate ◽  
Visible Absorption ◽  
Calf Thymus ◽  
Raman Study ◽  
Uv Visible

The binding of amsacrine [4′-(9-acridinylamino)methanesulfon- m-anisidide] to calf thymus DNA was studied by UV-visible and resonance Raman spectroscopy. A shift of the UV-visible absorption band of amsacrine at 434 to 442 nm together with a decrease in the intensity of this band is observed upon amsacrine-DNA binding. The resonance Raman spectrum of DNA-bound amsacrine shows a general slight decrease in intensity relative to the spectrum of the free species. The significant decrease in intensity of the bands at 1165, 1265, and 1380 cm−1 upon binding to DNA is attributed to the formation of a single amsacrine-DNA species. The assignment of these bands (1165, 1265, and 1380 cm−1), which was based upon a previous normal coordinate analysis (NCA) and molecular neglect of diatomic overlap (MNDO) calculation, and the observed lack of shift in the band positions upon binding are consistent with intercalation being the major binding mode of amsacrine, as inferred previously by other techniques.

Circular Dichroism and UV−Visible Absorption Spectra of the Langmuir−Blodgett Films of an Aggregating Helicene

1998 ◽  
Vol 120 (34) ◽  
pp. 8656-8660 ◽  
Author(s):  
Colin Nuckolls ◽  
Thomas J. Katz ◽  
Thierry Verbiest ◽  
Sven Van Elshocht ◽  
Hans-Georg Kuball ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Absorption Spectra ◽  
Visible Absorption ◽  
Langmuir Blodgett ◽  
Langmuir Blodgett Films ◽  
Uv Visible ◽  
Circular Dichroïsm

scholarly journals Binding of the Bi (III) Complex of Naringin with β-Cyclodextrin/Calf Thymus DNA: Absorption and Fluorescence Characteristics

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Sameena Yousuf ◽  
Israel V. Muthu Vijayan Enoch
Keyword(s):  
Inclusion Complex ◽  
Binding Constants ◽  
Calf Thymus Dna ◽  
Visible Absorption ◽  
X Ray ◽  
Fluorescence Measurements ◽  
Infrared Scanning ◽  
Calf Thymus ◽  
Fluorescence Characteristics ◽  
Uv Visible

Naringin-Bi (III) complex (Narb) was prepared and analysed by UV-Visible absorption and fluorescence measurements. The inclusion complex of Narb with β-Cyclodextrin (β-CD) was characterized by the UV-Visible absorption, Infrared, scanning dlectron microscopic, and X-ray diffractometric techniques. The stoichiometry of the inclusion complex of Narb with β-CD was 1 : 1 with a binding constant of 5.18 × 102 mol−1 dm3. The interaction of Narb with Calf Thymus DNA (ctDNA) was investigated in the presence and the absence of β-CD. The binding constants for the interaction of Narb with ctDNA in the absence and the presence of β-CD were 1.29 × 105 mol−1 dm3 and 6.89 × 104 mol−1 dm3, respectively. The Stern-Volmer constants for the interaction of Narb with ctDNA in the absence and the presence of β-CD were 1.25 × 104 mol−1 dm3 and 5.10 × 103 mol−1 dm3, respectively. The lowering of the binding affinity and the Ksv were observed for the interaction of Narb with ctDNA in the presence of β-CD.

scholarly journals Multi-Spectroscopic and Molecular Simulation Approaches to Characterize the Intercalation Binding of 1-Naphthaleneacetic Acid With Calf Thymus DNA

2021 ◽  
Vol 3 ◽  
Author(s):  
Xing Hu ◽  
Xiaoqiao Luo ◽  
Zhisheng Zhou ◽  
Rui Wang ◽  
Yaqin Hu ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Molecular Simulation ◽  
The Body ◽  
Calf Thymus Dna ◽  
Naphthaleneacetic Acid ◽  
Visible Absorption ◽  
Peak Intensity ◽  
Calf Thymus ◽  
Endogenous Fluorescence ◽  
Circular Dichroïsm

1–Naphthaleneacetic acid (NAA), having high-quality biological activity and great yield-increasing potential in agricultural production, is a broad-spectrum plant growth regulator. Although NAA is of low toxicity, it can affect the balance of the human metabolism and damage the body if it is used in high quantity for a long time. In this study, the interaction of NAA with calf thymus DNA (ctDNA) was investigated under simulated human physiological acidity (pH 7.4) using fluorescence, ultraviolet-visible absorption, and circular dichroism spectroscopy combined with viscosity measurements and molecular simulation techniques. The quenching of the endogenous fluorescence of NAA by ctDNA, observed in the fluorescence spectrum experiment, was a mixed quenching process that mainly resulted from the formation of the NAA–ctDNA complex. NAA mainly interacted with ctDNA through hydrophobic interaction, and the binding constant and quenching constant at room temperature (298 K) were 0.60 × 105 L mol−1 and 1.58 × 104 L mol−1, respectively. Moreover, the intercalation mode between NAA and ctDNA was verified in the analysis of melting point, KI measurements, and the viscosity of ctDNA. The results were confirmed by molecular simulation, and it showed that NAA was enriched near the C–G base of ctDNA. As shown in circular dichroism spectra, the positive peak intensity of ctDNA intensified along with a certain degree of redshift, while the negative peak intensity decreased after binding with NAA, suggesting that the binding of NAA induced the transformation of the secondary structure of ctDNA from B-form to A-form. These researches will help to understand the hazards of NAA to the human body more comprehensively and concretely, to better guide the use of NAA in industry and agriculture.

Effects of Two Trypsin Inhibitors on Trypsin in Activity and Structure

2014 ◽  
Vol 1073-1076 ◽  
pp. 1824-1827
Author(s):  
Shu Ting Dong ◽  
Hong Zhang ◽  
Na Xu ◽  
Ping Li ◽  
Si Si Xu ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Trypsin Inhibitor ◽  
Cd Spectroscopy ◽  
Trypsin Inhibitors ◽  
Kunitz Trypsin Inhibitor ◽  
Visible Absorption ◽  
Uv Visible ◽  
Circular Dichroïsm ◽  
Visible Absorption Spectroscopy ◽  
Inhibit Factor

Two reversible trypsin inhibitors, Kunitz trypsin inhibitor (KTI) and Bowman-Birk trypsin inhibitor (BBI) were compared to find the more optimal one as the inhibit factor during trypsin immobilization. Fluorescence spectroscopy, UV–visible absorption spectroscopy and circular dichroism (CD) spectroscopy were used to explore the effects of the two inhibitors on trypsin in activity and structure. The results showed that both inhibitors combined with trypsin in 1:1. CD circular dichroism spectroscopy showed that KTI and BBI led to different changes in trypsin second structure. The results can help us find out the mechanism between the two inhibitors and trypsin and select the more optimal inhibitor in trypsin immobilization.

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