The most remarkable conformational transition in nature is the B-to-Z transition of DNA which not only contributes for epigenetic regulation but also is exploited to create several advanced nanomaterials for sensing and nanomechanics. The present communication focuses on the intrinsic factors that control the La/Ce-induced B-to-Z transition in self-assembled branched DNA (bDNA) nanostructures. The transition is sensitive even to two nucleotide change in the loop length and overhang sequences. Predominantly, bDNA structures having 3 T loop length are more sensitive towards helical switching than the 5 T bearing structures. Particularly, bDNA US-17, US-19 and US-23 having 3 T in the loop are showing B-Z transition in presence of LaCl. Interestingly, with 'GATC' overhangs both La/Ce-induced B-to-Z transition was noticed in bDNA structures US-21 and US-22 (having 3 T and 5 T in the loop, respectively). The lanthanide-induced B-Z transition in bDNA is reversed with treatment of EDTA. Isothermal titration calorimetry (ITC) experiments show that the binding mode of lanthanide salts to bDNA followed an entropically and enthalpically favorable process. Further, for the first time ITC data suggests the B-to-Z transition in bDNA is a cooperative shift from exothermic to endothermic.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.ijbiomac.2019.06.166 | DOI Listing |
ACS Omega
November 2024
DNA Nanomaterials & Application Laboratory, Environment and Sustainability Department, CSIR-Institute of Minerals & Materials Technology, Bhubaneswar 751 013, India.
Rare earth elements have been shown to trigger the B-to-Z DNA transition in diverse self-assembled branched DNA architectures. Herein, we investigated the influence of cerium chloride on the conformational changes of DNA sequences containing repeated cytosine-guanine (CG) or guanine-cytosine (GC) sequences. The CD results show that (CG) repeats were susceptible to the formation of Z-DNA at low concentrations of CeCl.
View Article and Find Full Text PDFInt J Biol Macromol
May 2024
DNA Nanotechnology & Application Laboratory, Environment and Sustainability Department, CSIR-Institute of Minerals & Materials Technology, Bhubaneswar 751013, India; Academy of Scientific & Innovative Research (AcSIR), Ghaziabad 201002, India. Electronic address:
Zeta potential is commonly referred as surface charge density and is a key factor in modulating the structural and functional properties of nucleic acids. Although the negative charge density of B-DNA is well understood, there is no prior description of the zeta potential measurement of Z-DNA. In this study, for the first time we discover the zeta potential difference between B-DNA and lanthanum chloride-induced Z-DNA.
View Article and Find Full Text PDFImmunity
November 2023
Department of Pathogenic Biology, Key Laboratory of Infection and Immunity of Shandong Province, and Key Laboratory for Experimental Teratology of the Chinese Ministry of Education, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China. Electronic address:
Cyclic guanosine monophosphate (GMP)-AMP (cGAMP) synthase (cGAS) is a universal double-stranded DNA (dsDNA) sensor that recognizes foreign and self-DNA in the cytoplasm and initiates innate immune responses and has been implicated in various infectious and non-infectious contexts. cGAS binds to the backbone of dsDNA and generates the second messenger, cGAMP, which activates the stimulator of interferon genes (STING). Here, we show that the endogenous polyamines spermine and spermidine attenuated cGAS activity and innate immune responses.
View Article and Find Full Text PDFMethods Mol Biol
March 2023
Department of Precision Medicine, Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, South Korea.
The B-DNA to Z-DNA transition is a remarkable conformational change in DNA, which was originally observed in poly-GC DNA in the presence of high salt concentration. This eventually prompted the observation of the crystal structure of Z-DNA, a left-handed double-helical DNA, at atomic resolution. Despite advances in Z-DNA research, the application of circular dichroism (CD) spectroscopy as the fundamental technique to characterize this unique DNA conformation has remained constant.
View Article and Find Full Text PDFACS Omega
October 2022
Department of Chemistry, University of Colorado Denver, Science Building 1151 Arapahoe St, Denver, Colorado 80204, United States.
Oligonucleotides can be chemically modified for a variety of applications that include their use as biomaterials, in therapeutics, or as tools to understand biochemical processes, among others. This work focuses on the functionalization of oligonucleotides of RNA and DNA (12- or 14-nucleotides long) with methylbenzothiophene (BT), at the C2'-O-position, which led to unique structural features. Circular dichroism (CD) analyses showed that positioning the BT units on one strand led to significant thermal destabilization, while duplexes where each strand contained 4-BT rings formed a distinct arrangement with cooperativity/interactions among the modifications (evidenced from the appearance of a band with positive ellipticity at 235 nm).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!