Year-end Sale % OFF 
Abstract
BackgroundThe thermodynamics of the base pair specificity of the binding of the polyamines spermine, spermidine, putrescine, and cadaverine with three genomic DNAs Clostridium perfringens, 27% GC, Escherichia coli, 50% GC and Micrococcus lysodeikticus, 72% GC have been studied using titration calorimetry and the data supplemented with melting studies, ethidium displacement and circular dichroism spectroscopy results.Methodology/Principal FindingsIsothermal titration calorimetry, differential scanning calorimetry, optical melting studies, ethidium displacement, circular dichroism spectroscopy are the various techniques employed to characterize the interaction of four polyamines, spermine, spermidine, putersine and cadaverine with the DNAs. Polyamines bound stronger with AT rich DNA compared to the GC rich DNA and the binding varied depending on the charge on the polyamine as spermine>spermidine >putrescine>cadaverine. Thermodynamics of the interaction revealed that the binding was entropy driven with small enthalpy contribution. The binding was influenced by salt concentration suggesting the contribution from electrostatic forces to the Gibbs energy of binding to be the dominant contributor. Each system studied exhibited enthalpy-entropy compensation. The negative heat capacity changes suggested a role for hydrophobic interactions which may arise due to the non polar interactions between DNA and polyamines.Conclusion/SignificanceFrom a thermodynamic analysis, the AT base specificity of polyamines to DNAs has been elucidated for the first time and supplemented by structural studies.
Highlights
Polyamines (Fig. 1) are cardinal indispensible molecules which sustain the structure, conformation, and function of nucleic acids and proteins thereby affecting cell growth and orchestrate cellular regulatory pathways and functions like gene regulation, DNA packaging, proliferation etc [1,2,3,4,5,6]
It can be noted that the binding of the polyamines to Micrococcus lysodeikticus (ML) DNA resulted in a higher positive enthalpy than that for the Eschereria coli (EC) and Clostridium perfringens (CP) DNA
For spermidine- CP DNA the affinity value was of the order of 105 M21 while to EC and ML DNA the affinity was of the order of 104 M21
Summary
Polyamines (Fig. 1) are cardinal indispensible molecules which sustain the structure, conformation, and function of nucleic acids and proteins thereby affecting cell growth and orchestrate cellular regulatory pathways and functions like gene regulation, DNA packaging, proliferation etc [1,2,3,4,5,6]. The precise nature of the interaction of polyamines with DNA still remains obscure. NMR studies have indicated the importance of the chemical nature of the nitrogens located in the polyamines in binding. These studies contradict the simple notion that polyamines just behave as polycations with a hydrocarbon chain [17]. The thermodynamics of the base pair specificity of the binding of the polyamines spermine, spermidine, putrescine, and cadaverine with three genomic DNAs Clostridium perfringens, 27% GC, Escherichia coli, 50% GC and Micrococcus lysodeikticus, 72% GC have been studied using titration calorimetry and the data supplemented with melting studies, ethidium displacement and circular dichroism spectroscopy results
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
