Surprising roles of electrostatic interactions in DNA-ligand complexes.

نویسندگان

  • Shelley B Howerton
  • Akankasha Nagpal
  • Loren Dean Williams
چکیده

The positions of cations in x-ray structures are modulated by sequence, conformation, and ligand interactions. The goal here is to use x-ray diffraction to help resolve structural and thermodynamic roles of specifically localized cations in DNA-anthracycline complexes. We describe a 1.34 A resolution structure of a CGATCG(2)-adriamycin(2) complex obtained from crystals grown in the presence of thallium (I) ions. Tl(+) can substitute for biological monovalent cations, but is readily detected by distinctive x-ray scattering, obviating analysis of subtle differences in coordination geometry and x-ray scattering of water, sodium, potassium, and ammonium. Six localized Tl(+) sites are observable adjacent to each CGATCG(2)-adriamycin(2) complex. Each of these localized monovalent cations are found within the G-tract major groove of the intercalated DNA-drug complex. Adriamycin appears to be designed by nature to interact favorably with the electrostatic landscape of DNA, and to conserve the distribution of localized cationic charge. Localized inorganic cations in the major groove are conserved upon binding of adriamycin. In the minor groove, inorganic cations are substituted by a cationic functional group of adriamycin. This partitioning of cationic charge by adriamycin into the major groove of CG base pairs and the minor groove of AT base pairs may be a general feature of sequence-specific DNA-small molecule interactions and a potentially useful important factor in ligand design.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Syntheses, Characterization and Solvatochromism Study of Heteroleptic Chelated Copper(II) Complexes Containing N,N- dibezyl Substituted Ethylenediamine and Acetylacetonate Ligands

A series of new heteroleptic chelated copper(II) complexes that encompass N,N-dibezyl substituted derivative of ethylenediamine (X-diamine) and acetylacetonate (acac) were prepared.  The IR and electronic absorption spectra and the molar conductivity of the complexes are presented and discussed.  The molar conductivity values of the complexes in different solvents reveals a predominance of elec...

متن کامل

Theoretical study of - stacking interactions in substituted-coronene||cyclooctatetraene complexes: A system without direct electrostatic effects of substituents

Stability of the ;-; stacking interactions in the substituted-coronene||cyclooctatetraene complexes wasstudied using the computational quantum chemistry methods (where || denotes ;–; stackinginteraction, and substituted-coronene is coronene which substituted with four similar X groups; X =OH, SH, H, F, CN, and NO). There are meaningful correlations between changes of geometricalparameters and t...

متن کامل

Spectroscopic evidence of Cu(II) and Zn(II) complexes having amino acid based Schiff base: A special emphasis on in vitro antimicrobial, DNA binding and cleavage studies

A new Schiff base ligand (L) obtained by the condensation reaction of N-acetylaceto-otoluidineand 2-aminopropanoic acid (an amino acid), is used to synthesize four mononuclearcomplexes of [MLCl] and [ML2] types (where M = Cu(II) and Zn(II); L = Schiff base) bykeeping the metal and ligand ratio as 1:1 and 1:2 respectively. This ligand and its complexeshave been characterized on the basis of diff...

متن کامل

Interaction of Novel Ni2+, Cu2+ and VO2+ Complexes of a Tridentate Schiff Base Ligand with DNA, BSA and their Cytotoxic Activity

In this research, the interaction of [CuL(DMF)], [NiL(DMF)] and [VOL(DMF)] (where L = ((E)-4-((2-amino-5-nitrophenylimino)methyl)benzene-1,3-diol)) complexes derived from tridentate Schiff base ligand with bovine serum albumin (BSA) and DNA was investigated via electronic absorption and fluorescence spectroscopy. The Ultraviolet-Visible (UV-Vis) spectra exhibited an isosbestic point for the com...

متن کامل

Biologically vital metal-based antimicrobial active mixed ligand complexes: synthesis, characterization, DNA binding and cleavage studies

Few novel cobalt(II) and copper(II) complexes [M(fmp)3]Cl2, [M(fmp)(bpy)2]Cl2,[M(fmp)(phen)2]Cl2 and [M(fmp)(phen)(bpy)]Cl2 (fmp = 3-furan-2-ylmethylene-pentane-2,4-dione, phen = 1,10-phenanthroline, bpy = 2,2'-bipyridine) have been synthesized andcharacterized by elemental analyses, molar conductance, magnetic susceptibility measurements,IR, electronic, EPR, mass spectra and cyclic voltammetri...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Biopolymers

دوره 69 1  شماره 

صفحات  -

تاریخ انتشار 2003