Complexation of poly(Lys-Ala) and poly(Lys-Ala-Ala-Ala) with pectins and potassium oligogalacturonates

1988 ◽  
Vol 53 (11) ◽  
pp. 2833-2842 ◽  
Author(s):  
Slavomír Bystrický ◽  
Anna Malovíková ◽  
Tibor Sticzay ◽  
Karel Bláha
Keyword(s):  
Charge Density ◽  
Helical Structure ◽  
Local Mode ◽  
Side Chains ◽  
Specific Band ◽  
Esterification Degree ◽  
Superhelical Structure ◽  
Circular Dichroic

The selected model polypeptides poly(Lys-Ala) and poly(Lys-Ala-Ala-Ala) underwent a helix-forming interaction with potassium pectates and pectinates of various esterification degree (E) and with some potassium oligogalacturonates (n = 2-5, 9, 13). Formation of the complex quantitatively monitored by a circular dichroic measurement showed that the specific band distribution of charged side chains of lysine units at the surface of helical structure does not constitute grounds for the local mode of interaction. Potassium pectinate of esterification degree E 57%, corresponding to polypeptides by charge density, does not reveal enhanced complexation values. The complex-forming efficacy continuously decreases with the increase of the esterification degree of pectin. Saturation of charges of the polypeptide was achieved predominantly by the spatial action of the superhelical structure of D-galacturonate chains.

Formation of the poly(Lys-Ala-Ala) complex with pectin of various esterification degree

1986 ◽  
Vol 51 (8) ◽  
pp. 1772-1780 ◽  
Author(s):  
Slavomír Bystrický ◽  
Rudolf Kohn ◽  
Tibor Sticzay ◽  
Karel Bláha
Keyword(s):  
Charge Density ◽  
Spatial Model ◽  
Decisive Role ◽  
Low Density ◽  
Linear Charge ◽  
Linear Charge Density ◽  
Charge Densities ◽  
Α Helix ◽  
Esterification Degree ◽  
Superhelical Structure

The helix-forming interaction of poly(Lys-Ala-Ala) with potassium pectinates of various esterification degree (E 0-87%) was quantitatively investigated by circular dichroism spectra. The helix-forming effect of pectinates is significant even at a low density of carboxyl anions in the molecule at a high esterification degree. The mutual complementarity of linear charge density of both interacting polyions plays a decisive role. The charge densities of unesterified pectate and helical poly(Lys-Ala-Ala) are very close. Orientation of the potassium pectate macromolecule (E0%) in the proposed spatial model is parallel to the axis of poly(Lys-Ala-Ala) α-helix. Saturation of the polypeptide charge with pectinates of an esterification degree E > 0% is achieved through formation of a superhelical structure of the pectinate with a turn density corresponding to the equivalence of charge densities of both interacting components in the complex.

Effect of polymerization degree of oligogalacturonates and D-galacturonans on their circular dichroic spectra

1979 ◽  
Vol 44 (1) ◽  
pp. 167-173 ◽  
Author(s):  
Slavomír Bystrický ◽  
Rudolf Kohn ◽  
Tibor Sticzay
Keyword(s):  
Physicochemical Properties ◽  
Aqueous Solutions ◽  
Helical Structure ◽  
Monomeric Unit ◽  
Polymerization Degree ◽  
Cd Spectra ◽  
Circular Dichroic

The CD spectra of aqueous solutions of homopolymeric sodium oligogalacturonates and D-galacturonans of polymerization degree n = 1-64, as well as lower calcium oligogalacturonates (n = 1-5) were measured. Chiroptic properties were correlated with the polymerization degree in terms of optical superposition of monomeric unit increments. Interpretation of obtained data, respecting further physicochemical properties entitles to conclude that the conformation of macromolecules of D-galacturonan in solution is close to helical structure.

Synthesis and Helical Structure of Poly(N-butynylamide)s Having Various Side Chains, Where the Helix Is Highly Affected by the Methyl Branch and the Lactone Moiety

2008 ◽  
Vol 41 (4) ◽  
pp. 1086-1093 ◽  
Author(s):  
Yuji Suzuki ◽  
Junichi Tabei ◽  
Masashi Shiotsuki ◽  
Yoshihito Inai ◽  
Fumio Sanda ◽  
...  
Keyword(s):  
Helical Structure ◽  
Side Chains ◽  
Methyl Branch

scholarly journals Highly efficient stabilisation of meta-ethynylpyridine polymers with amide side chains in water by coordination of rare-earth metals

2015 ◽  
Vol 13 (6) ◽  
pp. 1700-1707 ◽  
Author(s):  
Hiroki Makida ◽  
Hajime Abe ◽  
Masahiko Inouye
Keyword(s):  
Rare Earth ◽  
Rare Earth Metal ◽  
Rare Earth Metals ◽  
Earth Metal ◽  
Helical Structure ◽  
Metal Salts ◽  
Side Chains ◽  
Highly Efficient

An amphiphilic meta-ethynylpyridine polymer with chiral amide side chains coordinated with rare-earth metal salts, especially strongly with Sc(iii), to stabilise its helical structure with CD enhancement.

scholarly journals Side Chain Effect of Hydroxypropyl Cellulose Derivatives on Reflection Properties

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1696 ◽  
Author(s):  
Kenichiro Hayata ◽  
Seiichi Furumi
Keyword(s):  
Bragg Reflection ◽  
Cholesteric Liquid Crystal ◽  
Hydroxypropyl Cellulose ◽  
Side Chains ◽  
Cellulose Derivatives ◽  
Thermally Induced ◽  
Alkyl Groups ◽  
Modeling Calculation ◽  
Phase Temperature ◽  
Esterification Degree

Some cellulose derivatives are known to exhibit thermotropic and lyotropic cholesteric liquid crystal (CLC) phases with a visible reflection feature by changing the side chains and mixing with specific solvents, respectively. Although many studies have been reported so far, most of the derivatives have the side chains of linear alkyl groups, but not the bulky phenyl groups. In this report, we synthesized a series of hydroxypropyl cellulose (HPC) derivatives that possessed both linear propionyl esters and bulky (trifluoromethyl)phenyl carbamates in the side chains. The reflection peaks of HPC derivatives shifted to longer wavelengths upon heating due to an increase in the CLC helical pitch. Such thermally induced shifting behavior of the reflection peak was crucially dependent on not only the propionyl esterification degree, but also the substituents in the side chains of HPC derivatives. When the side chains of HPC were chemically modified with both propionyl esters and bulky substituents such as 3,5-bis(trifluoromethyl)phenyl carbamates, the reflection peaks emerged at longer wavelengths at the same temperature. This probably happened because of the steric hindrance of bulky side chains, as supported by the empirical molecular modeling calculation. Although the occupied volumes of (trifluoromethyl)phenyl groups were independent of the CLC phase temperature with visible Bragg reflection, the substituent position, i.e., substituent orientation of trifluoromethyl groups affected the CLC phase temperature. Moreover, we found that the hydrogen bonds between carbamate moieties in the HPC side chains play an important role in the thermally induced shift of reflection peaks.

Circular dichroism of helical polynucleotide chains

1967 ◽  
Vol 297 (1448) ◽  
pp. 150-162 ◽  
Keyword(s):  
Circular Dichroism ◽  
Nucleic Acids ◽  
Helical Structure ◽  
Optical Rotatory Dispersion ◽  
Random Coil ◽  
Helical Conformation ◽  
Polyadenylic Acid ◽  
V Region ◽  
Circular Dichroïsm ◽  
Circular Dichroic

In contrast to relatively well developed experimental and theoretical studies on polypeptides and proteins (see Gratzer 1967 and McLachlan 1967, this volume) the investigation of optical activity of polynucleotides and nucleic acids were very restricted. The optical rotatory dispersion curves of polynucleotides examined in the visible and near u. v. fit one-term Drude equation regardless of the conformation (Fresco 1961; Levedahl & James 1957; Ts’o, Helmkamp & Sander 1962). Recent circular dichroism (c. d.) measurements of several polynucleotides and nucleic acids (figure 1) indicated clearly the presence of dichroic bands in the u. v. region of base absorption which can be related to the dissymmetrical helical conformation (Brahms 1963). The intensity of circular dichroic bands decreases strongly under the conditions in which the helical structure is unstable and goes to random coil form (Brahms 1964; Brahms & Mommaerts 1964). Thus polyadenylic acid (poly A ) is known according to X-ray data to exist at acid pH in a helical two strand and right handed conformation (Rich, Davies, Crick & Watson 1961). In acid solution the same polyadenylic acid exhibits strong circular dichroic bands which disappear at high temperature (figure 2).

A circular dichroic study of helical structure in flagellar dynein

Biochemistry ◽  
1990 ◽  
Vol 29 (20) ◽  
pp. 4839-4843 ◽  
Author(s):  
Gabor Mocz ◽  
I. R. Gibbons
Keyword(s):  
Helical Structure ◽  
Circular Dichroic

Mesophase and Optical Properties of Side Chain Copolyacrylate with Mesogens and OLLA Segments Side Chains

2011 ◽  
Vol 181-182 ◽  
pp. 397-400
Author(s):  
Ya Ping Liu ◽  
Zhuo Hua Li ◽  
Ling Min Sun ◽  
Run Tao Dong ◽  
Hong Ru Chen ◽  
...  
Keyword(s):  
Ring Opening ◽  
Optical Rotation ◽  
Helical Structure ◽  
Ring Opening Polymerization ◽  
Side Chain ◽  
Side Chains ◽  
Induce Effect ◽  
Phase Structures ◽  
Acrylate Esters ◽  
Phase Behaviors

Thermal properties and phase behaviors of series of newly synthesized copolyacrylate esters with oligomeric-L-LA (OLLA) segments (DP = 10-40) and mesogens as side chains were characterized. The OLLAs prepared by ring opening polymerization of L-LA with active HO-group were modified to form polymerizable acrylate esters and then copolymerized with polymerizable mesogens. The thermal behaviors of these copolyacrylate esters were studied by DSC and POM measurements and phase structures by XRD measurements. The mesogens showed very good induce effect on the formation of layered structures. CD measurements were used to determine the helical structure and the optical rotation power of the side chain copolyacrylate esters.

Formation of the poly(L-lysine) complex with pectin of various esterification degree

1985 ◽  
Vol 50 (5) ◽  
pp. 1097-1109 ◽  
Author(s):  
Slavomír Bystrický ◽  
Rudolf Kohn ◽  
Tibor Sticzay ◽  
Karel Bláha
Keyword(s):  
Complex Formation ◽  
Electrostatic Interaction ◽  
Polypeptide Chain ◽  
Cd Spectrum ◽  
Esterification Degree ◽  
Circular Dichroic

The circular dichroic (CD) measurement was chosen the tool to investigate the complex formation of poly(L-lysine) with potassium pectate or pectinate of various esterification degree (E). The polycation-polyanion (pectate, E 0%) 1 : 1 complex was quantitatively formed by an electrostatic interaction independently upon the excess of either component. The partial esterification of pectin resulted in a decrease of complex formation; this drop is at a 20% esterification degree low, at higher esterification degrees (46% and 64%) considerable, and at an esterification degree 86% the complex has not been formed at all. The polypeptide chain was present in the complex in an α-helical arrangement characterized by the CD spectrum; the potential spatial arrangements of the complex were proposed. The α-helical polypeptide component constitutes a core surrounded by a superstructure of D-galacturonan chains.

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