Functional biopolymers

Layered materials are of special interest for bio-immobilization due to the accessibility of large internal and external surface areas, potential to confine biomolecules within regularly organized interlayer spaces, and processing of colloidal dispersions for the fabrication of protein-clay films for electrochemical catalysis [83-90], These studies indicate that layered materials can serve as efficient support matrices to maintain the native structure and function of the immobilized biomolecules. Current trends in the synthesis of functional biopolymer nano composites based on layered materials (specifically layered double hydroxides) have been discussed in excellent reviews by Ruiz-Hitzky [5] and Duan [6] herein we focus specifically on the fabrication of bio-inorganic lamellar nanocomposites based on the exfoliation and ordered restacking of aminopropyl-functionalized magnesium phyllosilicate (AMP) in the presence of various biomolecules [91]. 

Ruiz-Hitzky, E., Dardar, M. and Aranda, P. (2005) Functional biopolymer nanocomposites based on layered solids. Journal of Materials Chemistry, 15,... 

A. T. Hagler, A. Lapicirella, Spatial Electron Distribution and Population Analysis of Amides, Carboxylic Acid, and Peptides, and Their Relation to Empirical Potential Functions , Biopolymers 1976, 1167-1200 A. T. Hagler, L. Leiserowitz, M. Tuval, Experimental and Theoretical Studies of the Barrier to Rotation about the N-C° and Ca-C Bonds ([Pg.369]

Following this reasoning, a rational route for proceeding calls for the deliberate and prudent exchange of functions or structural motifs or the addition of new ones in fully functional biopolymers and observe the consequences in terms of stability and catalytic activity. There is hope that a limited structural modification at one particular site will entail a locally limited response that can be dissected and analyzed. The results emerging in the context of the functional catalyst are expected to be more readily translated into measures to be taken for the improvement of catalytic function. 

Kurita, K. (2006). Chitin and chitosan Functional biopolymers from marine crustaceans. Mar. Biotechnol. 8,203-226. 

In an interesting illustration of the first strategy, Sakaguchi and coworkers covalently attached hemoglobin to an aminopropyl silica particle and then polymerized organoalkoxysilanes on the surface of the hemoglobin-modified silica particle.85 The template was removed via treatment with oxalic acid.85 In more recent work, Zhang and coworkers utilized a similar approach. In their case, the sphere was made from the functionalized biopolymer, chitosan.86 The model template protein, bovine serum albumin, was covalently attached to the chitosan microsphere and then coated with a composite sol prepared from TEOS and an aminosilane.86... 

Many nucleophile-containing polymers have been synthesized as the concrete or the abstract materialization of functional biopolymers. They have their own character-... 

S. Lifson and B. H. Zimm, Simplified theory of the helixcoil transition in DNA based on a grand partition function. Biopolymers 7 15-23 (1%3). 

Eamshaw DJ, Gait MJ. Modified oligoribonucleotides as site-specific probes of RNA structure and function. Biopolymers 1998 48 39-55. 

The bottleneck in the origin of life is the formation of the functional biopolymers— enzymes and nucleic acids. The answer cannot be the random polycondensation from a chaotic mixture of the monomers, as this process would afford an astronomic number of different chains—ca. 10 for chains with a polymerization degree of 60. Given that, the probability that the same chain is produced more than once by a random polymerization process is in first approximation equal to zero the single active individual macromolecule, even if formed, would decompose before it could be made again by another chance event. How then can active macromolecules be formed ... 

Microbial cell-wall-lytic enzymes are widely used in the laboratory for cell breakage, proto-plasting of yeasts and bacteria, and for studies of the structure and composition of microbial cell walls (J ). Recently lytic systems have come under consideration as a specific and chemically mild way to rupture microbial cells on an industrial scale (2 ). There appear to be attractive commercial applications of lytic systems for the recovery of enzymes, antigens and other recombinant products accumulated within cells, for upgrading of microbial biomass for food and feed uses (4 5) and for the manufacture of functional biopolymers from cell wall carbohydrates (6). 

Functionalized biopolymers have successfully taken over the era of synthetic polymers because they are cost effective, biodegradable, environmentally friendly and efficient. These biopolymers, after graft copolymerization and crosslinking, can be used for the sustained release of drugs. Based on relative rates of diffusion (Rjjff) and rate of polymer relaxation (R,, ), the diffusion of drugs depends upon the value of Diffusion Exponent (n). If n < 0.5, the R < R, . and if n a 1.0, the R. > whereas in case of n> 0.5 and < i.o, ... 

Chitosan has received considerable attention as a functional biopolymer for diverse pharmaceutical and biomedical applications. It is a nontoxic, biocompatible, and biodegradable polymer. Chitosans can be formulated as nanocarriers mainly by... 

O. G. Jones and D. J. McClements. Functional biopolymer particles Design, fabrication, and applications. Comprehensive Reviews in Food Science and Food Safety, 9(4) 374-397, 2010. 

Bekard IB, Asimakis P, Bertolini J, Dunstan DE (2011) The effects of shear flow on protein structure and function. Biopolymers 95 733-745... 

Lanzillotta, C., Pipino, A., Lips, D. New functional biopolymer natural fiber composites from agriculture resources. In Proceeding of amraal technical conference of the society of plastics engineers, vol. 60, pp. 2185 (2002)... 

Complex coacervates may be formed by synthetic polyelectrolytes, but also by biological polyelectrolytes, such as proteins, polysaccharides, and polynucleotides. The complexation allows for combining two or more desirable properties and/or to provide additional stability for otherwise highly labile functional biopolymers, such as proteins (cf. Chapter 13). 

Jones GO, McClements DJ (2010) Functional biopolymer particles design, fabrication, and application. Compr Rev Food Sci Food Safety 9 374-397... 

K. Kurita, Chitin and chitosan functional biopolymers from marine crustaceans. Marine Biotechnology, 8 (3), 203-226, 2006. 

The functional biopolymer matrix in biominerals is a multicomponent mixture with the possibility of all kinds of interactions and this makes the analysis of the individual polymer components difficult. Also, the biomineralization proteins are often polydisperse, have a non-globular shape and multiple charges and post translational modifications, which further hampers the protein separation. It is even more difficult to reveal their function as they are not only present in a polymer mixture with the associated possibUity of polymer interactions, but are furthermore often only active for a certain time. For example, in calcified parts of crustacean cuticles, 33 different proteins have already been identified [ 153] so that it is difficult to reveal the fimctions of individual biomineralization polymers. 

E. Ruiz-Hitzky, M. Dardera and P. Aranda, Functional biopolymer nanocomposites based on layered solids /. Mater. Chem., 15,3650-3662 (2005). 

---