Biopolymer backbone

Emulsification of cellulose or starch with water or ethanol, soap and a fatty acid is a performing method to allow the grafting of fatty chains onto the biopolymer backbone. An experimental design allowed to determine the best conditions to synthesize starch fatty esters with DS < 0,5 using natural raw materials as reagents. 

The effect of sodium hydroxide on the xanthan flow curves is more than that expected from the charge shielding mechanism observed with sodium chloride. One possible explanation of this effect is base-catalyzed fragmentation reactions [26,32]. Fragmentation reactions break the biopolymer backbone (cellulose-like structure) to smaller saccharide units. Consequently, the hydrodynamic radius of the biopolymer would decrease and the viscosity of the polymer solution would diminish. 

The backbone just mentioned is a polyamide and the pegs are the amino acid side chains. Why polyamide Because it has the capacity of freezing the biopolymer backbone into precise three-dimensional patterns. Flexibility is also achieved and is of considerable importance for conformational... 

Klosinski, P., Penczek, S. Teichoic Acids and Their Models Membrane Biopolymers withPolphosphate Backbones. Synthesis, Structure and Properties. Vol. 79, pp. 139—157. 

Schafer, L., M. Cao, and M. J. Meadows. 1995a. Predictions of Protein Backbone Bond Distances and Angles from First Principles. Biopolymers 35, 603-606. 

Clustering (association or aggregation) as a result of dissimilar parts within one chain molecule is well-known in the field of biopolymers a recent example in the field of synthetic polymers is provided by poly (p-nitrophenylmethacrylate) which in dimethylformamide (105) forms threefold clusters, presumably because of the difference in polarity of backbone and ester groups. Liquori (118) has presented proof for a double-stranded helix of isotactic and syndiotactic polymethylmethacrylate. 

Membrane Biopolymers with Polyphosphate Backbones Synthesis, Structure and Properties... 

Extended Arrangements of Peptides and Proteins. Amino acids are finked from the carboxyl to the amine with formation of an amide bond, often referred to as the peptide fink. The repeating (— N—C — CO—) unit is called the peptide or protein backbone. Peptides and proteins differ only in the number of amino acids present in the biopolymer chain. The cutoff is arbitrarily set. Often, but not always, a peptide is designated as having fewer than 100 amino acids and the protein possesses more. Backbone amide groups have been found to play a role in enzyme catalysis. 

With the seven-helix bundle construct in hand, we turned our attention to incorporation of the three extracellular (EC) loops. The cytoplasmic loops were disregarded because they would not be involved in molecular recognition between the receptor and the SFLLRN ligand. Extracellular loop 3, the smallest of the three EC loops, was added first via the loop-search routine in the Biopolymer mode of Sybyl. The loop backbone choices found in the Brookhaven PDB were examined in 3-D and selected on the basis of their fit to the overall protein structure. After the side chains were added to EC3, some of them had to be rotated to avoid unfavorable steric interactions with other parts of the protein. Then, the entire protein was energy minimized. Extracellular loop 1 was then added, followed by EC2, and each time the loop selection was made after analyzing the protein in 3-D. Side chains of amino... 

Binding enzymes to solid supports can be achieved via covalent bonds, ionic interactions, or physical adsorption, although the last two options are prone to leaching. Enzymes are easily bound to several types of synthetic polymers, such as acrylic resins, as well as biopolymers, e.g., starch, cellulose [52], or chitosan [53,54]. Degussa s Eupergit resins, for example, are used as enzyme carriers in the production of semisynthetic antibiotics and chiral pharmaceuticals [55], Typically, these copolymers contain an acrylamide/methacrylate backbone, with epoxide side groups... 

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