Biopolymer macromolecules

Fig. 3.5 Representation of a scheme of an experiment (upper set of drawings) and the obtained experimental results presented as AFM images (middle part) and cross-sectional profiles (bottom) that provides evidence of silica nucleation and shell formation on biopolymer macromolecules. Scheme of experiment. This includes the following main steps. 1. Protection of the mica surface against silica precipitation. It was covered with a fatty (ara-chidic) acid monolayer transferred from a water substrate with the Langmuir-Blodgett technique. This made the mica surface hydrophobic because of the orientation of the acid molecules with their hydrocarbon chains pointing outwards. 2. Adsorption of carbohydrate macromolecules. Hydrophobically modified cationic hydroxyethylcellulose was adsorbed from an aqueous solution. Hydrocarbon chains of polysaccharide served as anchors to fix the biomacromolecules firmly onto the acid monolayer. 3. Surface treatment by silica precursor. The mica covered with an acid mono-...

Additional evidence for silica nucleation on biopolymer macromolecules was furnished by experiments in which solutions of proteins were studied by dynamic light scattering. As an illustration, Figure 3.6 shows the relative intensity of light scattering versus the diameter of the scattering particles in solution with 1 wt.% of bovine serum albumin. Curve 1 presents the initial state where the protein was not yet treated with silica precursor. The measured... 

Fig. 3.7 Schematic drawings demonstrating the main features of two-stage (A) and one-stage (B) procedures leading to a difference in the morphology of the fabricated materials. (A) Sol nanoparticles initially prepared in the first stage (1, see also Figure 3.3) can self-assemble into a three-dimensional network when they are in direct contact with each other. Forthis reason, a gel formed after cross-linking (sol-gel transition) has a smaller volume (2). (B) The initial stage (1) is represented by a solution of entangled biopolymer macromolecules. The...

Excluded volume determines space occupancy in biopolymer solutions. Competition between macromolecules for space in a mixed solution determines the phase separation threshold. In a dilute solution of biopolymers, macromolecules hardly interact with one another, individual macromolecules are independent of one another, and biopolymers are cosoluble. The effects of spatial limitations are enhanced by the transition from a dilute mixed solution, to a semi-dilute biopolymer solution where molecules come into contact with one another, interact, compete for the same space, and do not mix in all proportions. 

ARs are used in molecular biology for obtaining spin-labelled macromolecules. These labels register slight changes in the macromolecule state [22]. With the help of spin labels, the conformational transformations of biopolymer macromolecules as well as changes in the structure of biomembranes and nucleic acids, have been studied. 

Gubarev A, Carrillo J-MY, Dobrynin AV (2009) Scale-dependent electrostatic stiffening in biopolymers. Macromolecules 42(15) 5851-5860. doi 10.1021/ma9008143... 

Now, we can define the above class (3) as enzymatic polymerization . Biosynth via classes (1) and (2) produce naturally occurring biopolymers (macromolecules) in almost all cases. Enzymatic polymerizations of class (3), on the other hand, allow us to produce not only naturally occurring bio-... 

Tao T 1969 Time-dependent fluorescence depolarization and Brownian rotational diffusion coefficients of macromolecules Biopolymers 8 609-32... 

Much of tire science of biocompatibility can be reduced to tire principles of how to detennine tire interfacial energies between biopolymer and surface. The biopolymer is considered to be large enough to behave as bulk material witli a surface since (for example) a water cluster containing only 15 molecules and witli a diameter of 0.5 nm already behaves as a bulk liquid [132] it appears tliat most biological macromolecules can be considered to... 

Analytical techniques that utilise biopolymers, ie, natural macromolecules such as proteias, nucleic acids, and polysaccharides that compose living substances, represent a rapidly expanding field. The number of appHcations is large and thus uses hereia are limited to chiral chromatography, immunology, and biosensors. 

Biopolymers Naturally occurring macromolecules that include proteins, nucleic acids, and polysaccharides. 

The consideration made above allows us to predict good chromatographic properties of the bonded phases composed of the adsorbed macromolecules. On the one hand, steric repulsion of the macromolecular solute by the loops and tails of the modifying polymer ensures the suppressed nonspecific adsorptivity of a carrier. On the other hand, the extended structure of the bonded phase may improve the adaptivity of the grafted functions and facilitate thereby the complex formation between the adsorbent and solute. The examples listed below illustrate the applicability of the composite sorbents to the different modes of liquid chromatography of biopolymers. 

The above results proved the potential viability of the adsorbed hydrophilic macromolecules as bonded phases in chromatography of biopolymers but it must be admitted that additional crosslinking of previously adsorbed macromolecules is usually needed in order to obtain stable composites. The cross-linked bonded polymeric phases, however, may suffer from the restricted flexibility of the chain segment and their steric repellency may be diminished. Moreover, the conformational adaptivity of cross-linked chains for binding with solutes is poorer than that of grafted or chemically bound macromolecules. 

The ionic strength dependence of intrinsic viscosity is function of molecular structure and protein folding, ft is well known that the conformational and rheological properties of charged biopolymer solutions are dependent not only upon electrostatic interactions between macromolecules but also upon interactions between biopolymer chains and mobile ions. Due electrostatic interactions the specific viscosity of extremely dilute solutions seems to increase infinitely with decreasing ionic concentration. Variations of the intrinsic viscosity of a charged polyampholite with ionic strength have problems of characterization. 

The parameters of Mark-Houwink for biopolymers may be varied with solvent and temperature (Chen et al. 2009, Chen Tsai 1998). This is because the macromolecule changes hydrodynamic radius with type solution and temperature via change in their chain... 

Branco M, Wagner N, Pochan D et al (2009) Release of model macromolecules from selfassembling peptide hydrogels for injectable delivery. Biopolymers 92 318-318... 

Most published work on the design and fabrication of nanostructures from biological macromolecules relate to DNA and proteins the use of other biopolymers, such as cyclodextrins [2], was far less developed. Because the use of DNA is intensively covered in Chapter 10 of this volume (also see Ref 3), as well as recently described by Seeman [4,5] this chapter will focus on proteins as a potential tool for the construction of nanostructures. Hence this chapter is focused on literature that may provide a basis for the identification of gnidelines, methodologies, and examples having potential for farther development of new protein-based composite nanostrnctnres integrating strnctnral and bioactive components. 

Synthetic examples include the poly(meth)acrylates used as flocculating agents for water purification. Biological examples are the proteins, nucleic acids, and pectins. Chemically modified biopolymers of this class are carboxymethyl cellulose and the lignin sulfonates. Polyelectrolytes with cationic and anionic substituents in the same macromolecule are called polyampholytes. 

Capillary electrophoresis offers several useful methods for (i) fast, highly efficient separations of ionic species (ii) fast separations of macromolecules (biopolymers) and (iii) development of small volume separations-based sensors. The very low-solvent flow (l-10nL min-1) CE technique, which is capable of providing exceptional separation efficiencies, places great demands on injection, detection and the other processes involved. The total volume of the capillaries typically used in CE is a few microlitres. CE instrumentation must deliver nL volumes reproducibly every time. The peak width of an analyte obtained from an electropherogram depends not only on the bandwidth of the analyte in the capillary but also on the migration rate of the analyte. 

The corresponding liquid-phase chemistry can be used to promote ion formation by appropriate choice of solvent and pH, salt addition to form M.Na+ or M.NH4+, and postcolumn addition of reagents. The primary applications of ESI-MS are in the biopolymer field. The phenomenon of routine multiple charging is exclusive to electrospray, which makes it a very valuable technique in the fine chemical and biochemical field, because mass spectrometers can analyse high-molecular-mass samples without any need to extend their mass range, and without any loss of sensitivity. However, with ESI, molecules are not always produced with a distribution of charge states [137], Nevertheless, this phenomenon somehow complicates the determination of the true mass of the unknown. With conventional low-resolution mass spectrometers, the true mass of the macromolecule is determined by an indirect and iterative computational method. 

The next important role of biopolymers in the processes after precursor nucleation is that their macromolecules can serve as a template for silica. This has been... 

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