A band at 1185 cm 1 occurs in the infrared spectra of nucleic acids their A-type conformation which has been reproduced literature, too.The absorbance this is pro- portional to fraction form DNA samp+es con- taining a mixture different forms.The 11.85 assigned tentatively vibration sugar-phosphate backbone with fairly high contribution from sugar moiety.Drastic dehydration films acrompanied by continuous intensity decrease indica- ting collapse form.

An algorithm for the study of gradual hydration phospholipid assemblies by means Fourier transform infrared (FTIR) spectroscopy is presented. A complete series diacyl phosphatidylcholines (PCs) including all possible analogues with palmitoyl and oleoyl residues, namely DPPC, DOPC, POPC, OPPC, was investigated at room temperature. The lipid samples were prepared as cast films probably consisting aligned multilamellar bilayers. range water activities studied in these regulated adsorption via...

Abstract The conformation of nucleic acids can be probed reliably by the geometrical arrangement PO 2 ‐ groups in backbone. phosphate is described two angles, θ OO and OPO, which determined several methods. In present paper, angles obtained for A, B, C forms DNA, experimentally ir linear dichroism (LD) oriented films as well theoretically from energy‐minimized structures. methodology angle determination spectra presented detail, elucidating potentialities limitations this method....

The charge-transfer theory of Puranik and Kumar for hydrogen bonding is applicable to the bonds formed between a variety aromatic adsorbates silanol groups both silica partially chlorinated silica, with predictable restrictions. From relative positions respective data points in diagrams correlating either ionization potentials or Hammett substituent constants infrared spectroscopic data, it can be concluded that, besides benzene methylbenzenes, styrene most halogenobenzenes also interact via...

FTIR spectroscopy is used to study structural aspects of ternary complexes formed by the cationic lipid dimyristoyltrimethylammoniumpropane (DMTAP), zwitterionic dimyristoylphosphatidylcholine (DMPC), and deoxyribonucleic acid (DNA). Spectra single components are compared with those obtained for both equimolar DMPC–DMTAP mixture lipid–DNA complex. The IR spectra mixed phases strongly dominated lipidic absorption bands. This allows one easily monitor, in particular, thermotropic phase...

The gradual hydration of phospholipid films can be effectively probed by Fourier transform infrared (FTIR) spectroscopy (cf. part I this series). hydration-induced changes observed for lipid IR-absorption bands are probably composed contributions arising from the effects both direct binding water molecules and thereby caused conformational phase transitions in assemblies, respectively. In article, an attempt is made to attribute some more indicative spectroscopic results these molecular...

Abstract To explore the interaction potential of phospholipids, we have studied hydration diacyl phosphatidylcholine (PC) and methylphosphocholine (MePC), a pertinent model compound, by ir spectroscopy. Related ab initio Hartree—Fock calculations were performed for MePC. Water is considered ideal as relevant probe molecule. Spectroscopic data MePC reveal strong influence bound water not only on phosphate groups but also onto putatively apolar CH n groups. The same could be demonstrated...

The chemical characteristics of the polar parts phospholipids as main components biological membranes were investigated by using infrared (IR) spectroscopy and theoretical calculations with water a probe molecule. logical key molecule used in this study is methylphosphocholine (MePC) it not only representative model for lipid headgroup but itself has significance. Isolated MePC forms compact (folded) structure which essentially stabilized two intramolecular C−H···O type hydrogen bonds. At...

The hydration of two peculiar unsaturated lipids with phosphatidylethanolamine (PE) and phosphatidylcholine (PC) headgroups, namely dioctadecadienoyl PC (DODPC) dioleoyl PE (DOPE), has been studied at room temperature by infrared (IR) spectroscopy including the linear dichroism. Oriented films these subjected to an atmosphere definite values relative humidity were investigated. choice DODPC DOPE was motivated their common property undergoing a lyotropic phase transition, which, in each case,...

Infrared linear dichroism (LD) measurements on films of the DNA-caffeine complex in terms relative humidity (r.h.) show two main effects. Firstly, there is an insertion caffeine molecules into DNA double helix (B form), as evidenced by a very strong parallel LD behaviour 745 cm-1 band due to C-H out-of-plane deformation vibration caffeine. Furthermore, high r.h. values modified B form occurs similar recently reported BRAHMS and coworkers for DNA-polypeptide complexes. The reversible B-A...

Two selected unsaturated lipids, dioctadecadienoylphosphatidylcholine (DODPC) and dioleoylphosphatidylethanolamine (DOPE), undergo "solvation-induced" transitions at room temperature upon progressive hydration, varied via ambient relative humidity (RH), as demonstrated in the preceding first part of this study. These are induced by uptake about one water molecule per lipid each case change headgroups from a frozen, quasi-crystalline to "melted" state. The partial molar enthalpy entropy have...